The daily sleep duration among college students is normally distributed with a mean of 8.13 and standard deviation of 1.87. You want to use a sample size such that 95% of the averages fall within +/- 15 minutes (.25 of an hour) of the true mean of 8.13. Determine the smallest number of students you need to sample.

Answers

Answer 1

Using the z-distribution, as we have the standard deviation for the population, it is found that 215 students must be sampled.

What is a t-distribution confidence interval?

The confidence interval is:

[tex]\overline{x} \pm z\frac{\sigma}{\sqrt{n}}[/tex]

In which:

[tex]\overline{x}[/tex] is the sample mean.z is the critical value.n is the sample size.[tex]\sigma[/tex] is the standard deviation for the sample.

The margin of error is:

[tex]M = z\frac{\sigma}{\sqrt{n}}[/tex]

In this problem, we have a 95% confidence level, hence[tex]\alpha = 0.95[/tex], z is the value of Z that has a p-value of [tex]\frac{1+0.95}{2} = 0.975[/tex], so the critical value is z = 1.96.

The margin of error is of M = 0.25, with a population standard deviation of [tex]\sigma = 1.87[/tex], hence we solve for n to find the minimum sample size.

[tex]M = z\frac{\sigma}{\sqrt{n}}[/tex]

[tex]0.25 = 1.96\frac{1.87}{\sqrt{n}}[/tex]

[tex]0.25\sqrt{n} = 1.96(1.87)[/tex]

[tex]\sqrt{n} = \frac{1.96(1.87)}{0.25}[/tex]

[tex](\sqrt{n})^2 = \left(\frac{1.96(1.87)}{0.25}\right)^2[/tex]

[tex]n = 214.9[/tex]

Rounding up, 215 students must be sampled.

More can be learned about the z-distribution at https://brainly.com/question/25890103


Related Questions

CHERRY PIE A circular cherry pie has a radius of 6 inches. If the pie is cut into 8 congruent slices, what is
the area of one slice to the nearest hundredth?
6 in.
16.35 in?
14.14 in?
19.72 in2
17.13 in?

Answers

the correct answer would be the 3rd option

3 and 15 find the range of missing side

Answers

Answer:

draw a square with a side length of 2.5 cm. label it CARL

Draw the circle with center A passing through C

draw SEGMENT CR

draw the straight line d passing through A and perpendicular to CR

Answer:

12 < x < 18

Step-by-step explanation:

Assuming these are 2 sides of a triangle, then

given 2 sides of a triangle , the 3rd side x is in the range

difference of 2 sides < x < sum of 2 sides , that is

15 - 3 < x <  15 + 3

12 < x < 18

Need help on number 10
If tan C is 3/4, find the sin C.

Answers

Answer:

sin C = 3/5

Step-by-step explanation:

see image.

It helps to draw a picture. Tan C is the ratio of the OPP/ADJ.

Pythagorean theorem or if you know Pythagorean triples are a shortcut to find the hypotenuse.

Once you know the hypotenuse, use the ratio for sine to solve the question. Sine is OPP/HYP.

see image.

Solve (image attached)

Answers

Answer:

70 degrees

Step-by-step explanation:

We know that a straight line is 180 degrees so this equation can be used:

80 + x + 30 = 180
110 + x = 180
x = 70

Hope this helps :)

Solve for x please :)

Answers

Answer:

see explanation

Step-by-step explanation:

look photo

[tex]\qquad\qquad\huge\underline{{\sf Answer}}♨[/tex]

The given pair of angles form linear pair, therefore their sum is equal to 180°

that is :

[tex]\qquad \sf  \dashrightarrow \:2(x - 26) + 3x + 2 = 180[/tex]

[tex]\qquad \sf  \dashrightarrow \:2x - 52 + 3x + 2 = 180[/tex]

[tex]\qquad \sf  \dashrightarrow \:5x - 50 = 180[/tex]

[tex]\qquad \sf  \dashrightarrow \:5x = 230[/tex]

[tex]\qquad \sf  \dashrightarrow \:x = 46 \degree[/tex]

Have a great day ~

spherical water tank of radius R = 5m is emptied through a small circular hole of radius r = 0.03 m at the bottom. The top of the tank is open to the atmosphere. The instantaneous water level h in the tank (measured from the bottom of the tank, at the drain) can be determined from the solution of the following ODE:
dh /dt =r²(2gh)^0.5/ 2hR-h²
where g = 9.81 m/s². If the initial (t = 0) water level is h=6.5 m, compute the time required to drain the tank to a level of h= 0.5m. Use the fourth-order Runge-Kutta method.

Answers

Answer:

water level is h=6.5 m, compute the time required to drain the tank to a level of h= 0.5m. Use the fourth-order Runge-Kutta method.

Step-by-step explanation:

water level is h=6.5 m, compute the time required to drain the tank to a level of h= 0.5m. Use the fourth-order Runge-Kutta method.

GIVING BRAINLEST NO LINKS I ONLY CROWN RIGHT ANSWERS!
Select the expression that represents the following statement: The sum of 6 and 8 multiplied by 4.

Answers

Answ

Step-by-step explanation:

Vocabulary


1. Volume: A measure of ________ occupied by a __________-________________ figure.


1. Base: The __________ on which an object _______.


1. Height: The ______ distance from top to bottom, creates a ___-degree angle with the base.


1. Inverse Operation: The ________ of a math operation; the opposite of addition is ________ and the opposite of multiplication is ________.

1. Diameter: A ________ line going from one side of a ______ to the other through the _______.


1. Radius: The distance from the ______ to the ______ of a ______; _____ of the diameter.

Volume of a Cylinder
A ____________ is a _____________________ object with a _________________ base and top.

To find the ____________ of a ______________ we use the following formula:

Answers

Answer:

Step-by-step explanation:

. Volume: A measure of _space  occupied by a _three dimensional _ figure.

1. Base: The surface on which an object stands on.

1. Height: The _vertical distance from top to bottom, creates a _90° degree angle with the base.

1. Inverse Operation: The opposite of a math operation; the opposite of addition is subtraction and the opposite of multiplication is division.

1. Diameter: A straight line going from one side of a point on a circle to the other through the _center.

1. Radius: The distance from the center to the point of a circle;or half of the diameter.

Volume of a Cylinder

A cylinder is a three dimensional object with a circular base and top.

To find the volume of a cylinder we use the following formula:πr²h

Divya spends all of her free time playing with her building blocks. She owns building block sets with 333 pieces, 555 pieces, and 101010 pieces. Divya knows she owns 555 sets with 555 pieces and 222 sets with 101010 pieces. She also knows that she averages 555 pieces per set. This information is summarized in the table below

Answers

Answer:

  5 sets

Step-by-step explanation:

The average number of pieces per set is the ratio of the total number of pieces to the total number of sets.

Let x represent the number of 3-piece sets. Then the total number of pieces is ...

  3x +5(5) +10(2) = 3x +45

The total number of sets is ...

  x +5 +2 = x +7

We want the ratio of these numbers to be 5 pieces per set:

  (3x +45)/(x +7) = 5

  3x +45 = 5x +35 . . . . . multiply by (x+7)

  10 = 2x . . . . . . . . . . subtract (3x+35)

  5 = x . . . . . . . . . divide by 2

Divya owns 5 sets with 3 pieces.

_____

Alternate solution

Each 10-piece set has 5 more pieces than average, so the two of them total 10 more pieces than average.

Each 3-piece set has 2 fewer pieces than average. The total number of 3-piece sets must have a total of 10 fewer pieces than average in order to balance the excess of the 10-piece sets. That is, there must be 10/2 = 5 of the 3-piece sets to have a total lof 10 fewer pieces than average.

Altogether, the differences from average must total zero.

Eva filled a bucket with 7 gallons of water. A few minutes later, she realizes only 1 3/5 of water remained. How much water had leaked out of the bucket?

Answers

Answer:

[tex]6 \frac{2}{5}[/tex]

Step-by-step explanation:

[tex]7 - 1 \frac{3}{5} = 6 \frac{2}{5}[/tex]

LOOK AT PICTURE!!! DO THE QUESTION THAT IS CIRCLED. IF CORRECT 50 POINTS!

Answers

Answer:

v = length x width x hight

. A particle moves on a line away from its initial position so that after t seconds its distance is s = 3t^2+tmeters from its initial position. (a) At what time does the particle have a velocity of 25 m/s? (b) Is the acceleration ever 0? Why or why/not? Explain your answer
pls solve and explain fast​

Answers

Answer:

The velocity of this particle is [tex]25\; {\rm m \cdot s^{-1}}[/tex] at [tex]t = 4\; {\rm s}[/tex].

Acceleration is constantly [tex]6\; {\rm m\cdot s^{-2}}[/tex] (and thus is never [tex]0[/tex].)

Step-by-step explanation:

The distance between the particle and the initial position is the displacement of this particle. Let [tex]x(t)[/tex] denote the displacement (in meters) of this particle at time [tex]t[/tex] (in seconds.) The question states that [tex]x(t) = 3\, t^{2} + t[/tex].

Differentiate displacement [tex]x(t)[/tex] with respect to time [tex]t[/tex] to find the velocity [tex]v(t)[/tex] (in [tex]{\rm m \cdot s^{-1}}[/tex]) of this particle:

[tex]\begin{aligned}v(t) &= \frac{d}{d t}\left[x(t)\right] \\ &= \frac{d}{d t}\left[3\, t^{2} + t\right] \\ &= 6\, t + 1 \end{aligned}[/tex].

Set velocity to [tex]25\; {\rm m\cdot s^{-1}}[/tex] and solve for time [tex]t[/tex] (in seconds):

[tex]v(t) = 25[/tex].

[tex]6\, t + 1 = 25[/tex].

[tex]t = 4[/tex].

Thus, the velocity of this particle is [tex]25\; {\rm m \cdot s^{-1}}[/tex] at [tex]t = 4\; {\rm s}[/tex].

Differentiate velocity [tex]v(t)[/tex] with respect to time [tex]t[/tex] to find the acceleration (in [tex]{\rm m\cdot s^{-2}}[/tex]) of this particle:

[tex]\begin{aligned}a(t) &= \frac{d}{d t}\left[v(t)\right] \\ &= \frac{d}{d t}\left[6\, t + 1\right] \\ &= 6\end{aligned}[/tex].

In other words, the acceleration of this particle is constantly equal to [tex]6\; {\rm m\cdot s^{-2}}[/tex]. Hence, the acceleration of this particle is never [tex]0[/tex].

A rule for creating a pattern is given below. The rule begins with a number called the input and creates a number called the output.

Rule: Multiply the input by 5. Then subtract 4 from the result to get the output.

Which input and output table works for the rule?

Choose 1 answer:

(Choice A)

Input: 5 Output: 5

(Choice B)

Input: 3 Output: 7

(Choice C)

Input: 2 Output: 6

Answers

Answer:

Choice C - Input: 2 Output: 6

Answer:

C

Step-by-step explanation:

evaluate the output for the given input values using the rule

choice A

5 × 5 - 4 = 25 - 4 = 21 ≠ 5

choice B

3 × 5 - 4 = 15 - 4 = 11 ≠ 7

choice C

2 × 5 - 4 = 10 - 4 = 6 ← equals the output value

Find the value of x. 50 degrees 75 degrees

Answers

Answer:

The angles measure for x is.... 58 Degrees

Step-by-step explanation:

Something you have to remember with dealing with Triangles is that the three angles will always add up to 180 degrees. so if you have two of the angle already then you can solve for the 3rd one all you have to do is...

add both of the known angles

50 + 75 = 125

Now subtract 180 by 125

180 -125 = 58

Now you have your answer

58 Degrees!!!



You randomly draw twice from this deck of cards
0 с G|F. D C G
What is the probability of not drawing a C, then not drawing a C,
without replacing the first card? Write your answer as a decimal
rounded to the nearest hundredth.

Answers

The probability of not drawing C in neither draw is P = 0.5

How to get the probability?

All the cards have the same probability of being drawn, in this case, our set of cards is {F, D, C, G}

The probability of not drawing C is equal to the probability of drawing F, D or G. So we have 3 options out of 4, then the probability is:

p = 3/4.

Now we draw another, this time there are 3 cards, one of these is C, and the other two cards are not C. Then the probability of not drawing C again is equal to 2 over 3.

q = 2/3.

The joint probability (for both of these events to happen) is equal to the product of the individual probabilities:

P = p*q = (3/4)*(2/3) = 0.5

If you want to learn more about probability, you can read:

https://brainly.com/question/251701

Sita saves Rs. 1 today, Rs. 2 the next day, Rs. 4 the succeeding day and so on (each saving being twice of the preceding one). What will be total saving in two weeks time?
a

Answers

Answer:

Rs. 32767

Step-by-step explanation:

Because the amount is doubling every day, we can use the expression 1*2^15-1 because there is 1 to start with. Also cool trick! if you need to do 2^1+2^2+2^3+....+2^x, it will be equal to 2^(x+1)-1. So:

2^15-1

32768-1

32767

How do I solve it the problem completely

Answers

Answer:

42 in²

Step-by-step explanation:

Total: Shape 1 + Shape 2

Area of a square: l x w, where l is the length and w is the width.

= 6 x 5

= 30

Area of a triangle: 1/2 x b x h, where b is the base and h is the height.

= 1/2 x 4 x 6

= 1/2 x 24

= 12

Total = 30 + 12

= 42 in²

Answer:

Step-by-step explanation:

This figure is trapezium

a and b are the parallel lines.

a = 5 +4 = 9 in  & b = 5 in   and h = 6 in

[tex]\boxed{\text{Area of trapezium =$\dfrac{(a+b)*h}{2}$}}[/tex]

                              [tex]\sf = \dfrac{(9+5)*6}{2}\\\\=\dfrac{14*6}{2}\\\\= 7*6\\\\= 42 \ in^{2}[/tex]

How do you know that the Pythagorean Theorem is true?

Answers

The fact that the angles in a triangle add up to 180 indicates that it is actually a square). There are also four right triangles, each with a base and a height. The Pythagorean Theorem is reached when a2 + b2 = c2.

Find the multiplicative inverse of 6/8

Answers

It's 8/6

Because 6/8 × 8/6 = 1

Answer:

it's 8/6

I hope it's help u

. Gemma plans to run 5 miles her first week and increase the amount she runs each week by 20% Which of the following is closest to the total distance Genna has run after 10 weeks.

A: 115 miles. B: 130 miles

C: 138 miles. D: 145 miles​

Answers

the answer is obviously D because of the amout of miles ran each week

will give brainliest but it Has to be correct.
Measure the thumbtack to the nearest inch.
6/8 inches
7/8 inches
3/8 inches
5/8 inches

Answers

Answer: 6/8 inch

Step-by-step explanation:

How can i prove this property to be true for all values of n, using mathematical induction.

ps: spam/wrong answers will be reported and blocked.​

Answers

Proof -

So, in the first part we'll verify by taking n = 1.

[tex] \implies \: 1 = {1}^{2} = \frac{1(1 + 1)(2 + 1)}{6} [/tex]

[tex] \implies{ \frac{1(2)(3)}{6} }[/tex]

[tex]\implies{ 1}[/tex]

Therefore, it is true for the first part.

In the second part we will assume that,

[tex] \: { {1}^{2} + {2}^{2} + {3}^{2} + ..... + {k}^{2} = \frac{k(k + 1)(2k + 1)}{6} }[/tex]

and we will prove that,

[tex]\sf{ \: { {1}^{2} + {2}^{2} + {3}^{2} + ..... + {k}^{2} + (k + 1)^{2} = \frac{(k + 1)(k + 1 + 1) \{2(k + 1) + 1\}}{6}}}[/tex]

[tex] \: {{1}^{2} + {2}^{2} + {3}^{2} + ..... + {k}^{2} + (k + 1)^{2} = \frac{(k + 1)(k + 2) (2k + 3)}{6}}[/tex]

[tex]{1}^{2} + {2}^{2} + {3}^{2} + ..... + {k}^{2} + (k + 1)^{2} = \frac{k (k + 1) (2k + 1) }{6} + \frac{(k + 1) ^{2} }{6} [/tex]

[tex]{1}^{2} + {2}^{2} + {3}^{2} + ..... + {k}^{2} + (k + 1)^{2} = \frac{k(k+1)(2k+1)+6(k+1)^ 2 }{6} [/tex]

[tex]{1}^{2} + {2}^{2} + {3}^{2} + ..... + {k}^{2} + (k + 1)^{2} = \frac{(k+1)\{k(2k+1)+6(k+1)\} }{6}[/tex]

[tex]{1}^{2} + {2}^{2} + {3}^{2} + ..... + {k}^{2} + (k + 1)^{2} = \frac{(k+1)(2k^2 +k+6k+6) }{6} [/tex]

[tex]{1}^{2} + {2}^{2} + {3}^{2} + ..... + {k}^{2} + (k + 1)^{2} = \frac{(k+1)(2k^2+7k+6) }{6} [/tex]

[tex]{1}^{2} + {2}^{2} + {3}^{2} + ..... + {k}^{2} + (k + 1)^{2} = \frac{(k+1)(k+2)(2k+3) }{6} [/tex]

Henceforth, by using the principle of mathematical induction 1²+2² +3²+....+n² = n(n+1)(2n+1)/ 6 for all positive integers n.

_______________________________

Please scroll left - right to view the full solution.


An airplane flies with a constant speed
of 840 km/h. How far can it travel in
1 hour?

Answers

Answer:

  840 km

Step-by-step explanation:

The speed expression ...

  840 kilometers per hour

means the plane files 840 kilometers in each hour.

In 1 hour, it will travel 840 km.

PLEASE HELP PLEASE PLEASE HELP

Answers

Answer:

Our Sun is a bright, hot ball of hydrogen and helium at the center of our solar system. It is 864,000 miles (1,392,000 km) in diameter, which makes it 109 times wider than Earth. It's 10,000 degrees Fahrenheit (5,500 degrees Celsius) at the surface, and 27 million degrees Fahrenheit (15,000,000 degrees Celsius) in the core.

Step-by-step explanation:

did this help

The Sun is the star at the center of the Solar System. It is a nearly perfect sphere of hot plasma, heated to incandescence by nuclear fusion reactions in its core, radiating the energy mainly as visible light and infrared radiation. It is by far the most important source of energy for life on Earth.                        maybe this will help a little

What is the equation for the translation of x2 + y2 = 16 seven units to the right and five units up?

(x + 7)2 + (y + 5)2 = 16

(x − 7)2 + (y − 5)2 = 16

(x + 7)2 + (y − 5)2 = 16

(x − 7)2 + (y + 5)2 = 16

Answers

Answer:

(x − 7)2 + (y − 5)2 = 16

Step-by-step explanation:

The given circle has equation

[tex] \sf \: x^2+y^2=16x[/tex]

The equation of a circle with center (h,k) and radius r units is

[tex] \sf(x-h)^2+(y-k)^2=r^2(x−h) [/tex]

[tex] \sf(x-7)^2+(y-5)^2=4^2(x−7)[/tex]

[tex] \sf(x-7)^2+(y-5)^2=16(x−7) [/tex]

❖ Tip❖ :-

This is the equation that has its center at the origin with radius 4 units.

When this circle is translated seven units to the right and five units up, then the center of the circle will now be at (7,5).

Evaluate the expression when g=5 and h=33.
h-4g

Answers

Answer:145

Step-by-step explanation:

if h=33 and g=5 the expression would look like 33-4x5 frist 33-4=29 so now we imes by 5, 29x5=145 so 145 is your answer

i need help
Simplify the expression 63 + 5(4 − 2).

28
36
226
234

Answers

Answer:

226

Step-by-step explanation:

Given:

Simplify 6^3+5(4-2)

Note:

I think you meant 6^3 because if you solve 63+5(4-2):

63+5(4-2)

63+5 * 2

63 + 10

73
Solve:

6^3 + 5(4 - 2 )    

6^3 + 5 x 2

6 x 6 x 6 = 216

226 + 5 x 2

5 x 2 = 10

216 + 10 = 226

~Lenvy~

Determine the values of k for which the function f(x) = 4x^2-3x + 2kx + 1 has two zeros. Check these values in the original equation. ​

Answers

k must be greater than or equal to 22.75 to have two different zeros.

How to determine the value of missing coefficient in second order polynomials

Second order polynomials are algebraic expressions that observe the following form:

[tex]p(x) = a\cdot x^2 + b\cdot x + c[/tex]   (1)

Where:

a, b, c - Coefficientsx - Independent variable

For polynomials of the form p(x) = 0, we can infer the nature of their roots by applying the following discriminant:

d = b² - 4 · a · c   (2)

According to (2), there are three cases:

If d < 0, then there are two conjugated complex roots.If d = 0, then the two roots are the same real number.If d > 0, then the two roots are two distinct real numbers.

Now we have the following discriminant case:

-(3 + 2 · k)² - 4 · (1) · (4) ≠ 0

-(9 + 6 · k + 4 · k²) - 16 ≠ 0

-9 - 6 · k - 4 · k² - 16 ≠ 0

4 · k²+ 6 · k +25 ≠ 0

This characteristic polynomial has two conjugated complex roots, then we conclude that all values of k must positive or negative, but never zero. By graphng tools we find that k must be greater than or equal to 22.75 to have two different zeros.

To learn more on polynomials, we kindly invite to check this verified question: https://brainly.com/question/11536910

add the integers (-14)+(-31)​

Answers

Answer:

[tex]-45[/tex]

Step-by-step explanation:

add the negative numbers together, and the solution stays negative.
[tex](-14) + (-31) = -45[/tex]

the equation y=|x|+1 is graphed and then transformed. the transformation is on the graph below. which of the following describes this transformation.
a. up 1 unit
b. down 1 unit
c. right 2 units, down 1 unit
d. right 2 units, down 2 units

Answers

Answer:

a.  up 1 unit

Step-by-step explanation:

f(x) + k will translate the function up k units

f(x) - k will translate the function down k units

f(x-h) will translate the function right h units

f(x+h) will translate the function left h units

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