How can you help this student make sense of her method?
ONLY ANSWER IF YOU KNOW THE ANSWER

Answer:

(a) The sample variance is 16.51

(a) The sample standard deviation is 4.06

Step-by-step explanation:

Given

[tex]\begin{array}{cc}{Class} & {Frequency} & 8.26 - 10.00 & 20 &10.01-11.75 & 38 &11.76 - 13.50& 36 & 13.51-15.25 &25&15.26-17.00 &27 &\ \end{array}[/tex]

Solving (a); The sample variance.

First, calculate the class midpoints.

This is the mean of the intervals.

i.e.

[tex]x_1 = \frac{8.26+10.00}{2} = \frac{18.26}{2} = 9.13[/tex]

[tex]x_2 = \frac{10.01+11.75}{2} = \frac{21.76}{2} = 10.88[/tex]

[tex]x_3 = \frac{11.76+13.50}{2} = \frac{25.26}{2} = 12.63[/tex]

[tex]x_4 = \frac{13.51+15.25}{2} = \frac{28.76}{2} = 14.38[/tex]

[tex]x_5 = \frac{15.26+17.00}{2} = \frac{32.26}{2} = 16.13[/tex]

So, the table becomes:

[tex]\begin{array}{ccc}{Class} & {Frequency} & {x} & 8.26 - 10.00 & 20&9.13 &10.01-11.75 & 38 &10.88&11.76 - 13.50& 36 &12.63& 13.51-15.25 &25&14.38&15.26-17.00 &27 &16.13\ \end{array}[/tex]

Next, calculate the mean

[tex]\bar x = \frac{\sum fx}{\sum f}[/tex]

[tex]\bar x = \frac{20*9.13 + 38 * 10.88+36*12.63+25*14.38+27*16.13}{20+38+36+25+27}[/tex]

[tex]\bar x = \frac{1845.73}{146}[/tex]

[tex]\bar x = 12.64[/tex]

Next, the sample variance is:

[tex]\sigma^2 = \frac{\sum f(x - \bar x)^2}{\sum f - 1}[/tex]

So, we have:

[tex]\sigma^2 = \frac{20*(9.13-12.63)^2 + 38 * (10.88-12.63)^2 +...........+27 * (16.13 -12.63)^2}{20+38+36+25+27-1}[/tex]

[tex]\sigma^2 = \frac{2393.6875}{145}[/tex]

[tex]\sigma^2 = 16.51[/tex]

The sample standard deviation is:

[tex]\sigma = \sqrt{\sigma^2}[/tex]

[tex]\sigma = \sqrt{16.51}[/tex]

[tex]\sigma = 4.06[/tex]

Explanation:

x is the number of years since 1988

x = 0 represents the year 1988

x = 1 is the year 1988+1 = 1989

x = 2 is the year 1988+2 = 1990

etc

x = 32 is the year 1988+32 = 2020

Answer:

thiếu giữ liệu không thể trả lời được

Step-by-step explanation:

Answer:

Value of 7.34 centimeter into meter is 0.0734

Step-by-step explanation:

Given value;

7.34 centimeter

Find:

Value of 7.34 centimeter into meter

Computation:

We know that

⇒ 1 centimeter = 0.01 meter

So,

⇒ 7.34 centimeter = 7.34 x 0.01

⇒ 7.34 centimeter = 7.34 x 1/100

⇒ 7.34 centimeter = 7.34 / 100

⇒ 7.34 centimeter = 0.0734 meter

Value of 7.34 centimeter into meter is 0.0734

The probability that a marble chosen at random is shaded or is labeled with a multiple of 3 is 6/11.

We have given that options

Two-elevenths

Three-elevenths

Five-elevenths

Six-elevenths

We have to determine the probability that a marble chosen at random is shaded or is labeled with a multiple of 3.

Probability is an event is to occur, or how likely it is that a proposition is true. The probability of an event is a number between 0 and 1, where, roughly speaking, 0 indicates the impossibility of the event and 1 indicates certainty.

Therefore the probability that a marble chosen at random is shaded or is labeled with a multiple of 3 is 6/11.

To learn more about the probability visit:

https://brainly.com/question/25870256

#SPJ2

6/11

Step-by-step explanation:

Answer:

4 StartRoot 3 EndRoot units

Hope this answer is right!!

Step-by-step explanation:

Since AD is perpendicular to BC, so ΔABD will be aright-angled triangle. Thus, the length of the altitude is 4√3 units.

The length of the altitude of the equilateral triangle is 4√3  units.

The given parameters;

The half length of the base of the triangle is calculated as follow;

[tex]x = \frac{8 \ units}{2} \\\\x = 4 \ units[/tex]

The height of the triangle is calculated by applying Pythagoras theorem as follows;

[tex]h^2 = L^2 - x^2\\\\h = \sqrt{(8^2) - (4^2)} \\\\h = \sqrt{48} \\\\h = \sqrt{16 \times 3} \\\\h = 4\sqrt{3} \ \ units[/tex]

Thus, the length of the altitude of the equilateral triangle is 4√3  units.

Learn more about equilateral triangle here: https://brainly.com/question/15294703

Answer is

5 gives the range of possible values for x.

Answer:

2cm

Step-by-step explanation:

vbjufdxcvhjjkknvxzdhjkbcxdf

Answer:

Volume = h * w * l (height, width, length)

Volume = 4* 6 * 3

Volume = 72 cube meters

Surface area is finding the are of every 2D plane on the solid.

2(w * h) + 2(l*h) + 2(w * l)

Surface are = 108 square meters

Answer: 12

Step-by-step explanation: Since the angles are supplements, 3x + x - 20 = 180. Solving this, we find that x = 50, and 3x = 150. Since dodecagons have interior angles of 150 degrees, the answer is 12 sides.

Answer:

Step-by-step explanation:

Since the angles are supplements, 3x + x - 20 = 180. Solving this, we find that x = 50, and 3x = 150. Since dodecagons have interior angles of 150 degrees, the answer is 12 sides.

Answer:

20 minutes

Step-by-step explanation:

20 minutes after 3:15 is 3:35, then 5 more minutes is 3:40. Therefore Sten has 20 minutes left until 4pm.

Answer:g(x) = 3/2x + 2 and a half?

Step-by-step explanation: sorry not good at college math, but at least i tried.

Answer:

[tex]M = (0,0)[/tex]

Step-by-step explanation:

Given

[tex](4,-5)[/tex] and [tex](-4,5)[/tex]

Required

The midpoint (M)

This is calculated as:

[tex]M = \frac{1}{2}(x_1 + x_2,y_1+y_2)[/tex]

So, we have:

[tex]M = \frac{1}{2}(4-4,-5+5)[/tex]

[tex]M = \frac{1}{2}(0,0)[/tex]

[tex]M = (0,0)[/tex]

Answer:

option : b, c

Step-by-step explanation:

1 meter = 100 centimeters

45 meters = 4500 centimeters

1000 meter = 1 kilometer

 [tex]45 \ meters = \ \frac{45}{1000} = 0.045 \ kilometers[/tex]

1 meter = 1000 millimeters

45 meters = 45, 000 millimeters

Answer:

2x^2 + 4

Step-by-step explanation:

f(g(x)) just means to first solved g(x) and put the solution into f(x).

Therefore, it becomes f(x)=(10x^2+5)/5 + 3, and you can simplify that into

2x^2 + 4.

Answer:

[tex]x-2y=3[/tex]

Step-by-step explanation:

[tex]We\ are\ given,\\Line\ passes\ through\ the\ points\ (1,-1) and (9,3). Hence,\ this\ means\ that\ the\\ points\ are\ indeed\ solutions\ of\ the\ equation,\ which\ represents\ the\ line.\\Hence,\\We\ know\ that,\\The\ equation\ of\ a\ line\ (Point-Slope)\ is\ given\ by:\\y-y_1=m(x-x_1),\ where\ m\ is\ the\ slope\ of\ the\ graph.[/tex]

[tex]So\ first,\\Lets\ find\ the\ Slope\ of\ the\ Graph.\\Slope(m)=\frac{Rise}{Run}=\frac{y_2-y_1}{x_2-x_1}\\Hence,\\Here,\\Considering\ (1,-1)\ as\ the\ First\ Point\ and\ (9,3)\ as\ the\ Second\ Point,\ we\ have:x_1=1,x_2=9\ and\ y_1= -1, y_2=3\\Plugging\ the\ values\ in\ the\ Equation\ for\ the\ Slope,\ we\ have:\\[/tex]

[tex]m=\frac{y_2-y_1}{x_2-x_1}=\frac{3-(-1)}{9-1}=\frac{3+1}{9-1}= \frac{4}{8}=\frac{1}{2}\\Hence,\\Coming\ back\ to\ our\ Point-Slope\ Formula\ for\ the\ equation:\\\ We\ already\ have:\\y-y_1=m(x-x_1)\\Substituting\ m=\frac{1}{2} , x_1=1,\ y_1=-1,\ we\ have: \\y+1=\frac{1}{2}(x-1)\\\therefore 2(y+1)=x-1\\\therefore 2y+2=x-1\\\therefore 2y-x=-3\\Multiplying\ with\ (-1)\ on\ both\ sides:\\\therefore x-2y=3\\Hence,\\x-2y=3,\ is\ our\ desired\ equation.[/tex]

the answer is b no trend

Answer:

The correct answer is:

(a) 0.54

(b) 0.0385

Step-by-step explanation:

Given:

Restaurant tax,

p = 0.54

Sample size,

n = 168

Now,

(a)

The mean will be:

⇒ μ [tex]\hat{p}= p[/tex]

         [tex]=0.54[/tex]

(b)

The standard error will be:

[tex]\sigma \hat{p}[/tex] = [tex]\sqrt{[\frac{p(1-p)}{n} ]}[/tex]

    = [tex]\sqrt{[\frac{(0.54\times 0.46)}{168} ]}[/tex]

    = [tex]\sqrt{[\frac{(0.2484)}{168} ]}[/tex]

    = [tex]0.0385[/tex]

Answer:

That is Arithmetic

Step-by-step explanation:

Arithmetic Sequence is described as a list of numbers, in which each new term differs from a preceding term by a constant quantity. Which is -5 in this case.

Hope this helps

Answer:

Adult ticket = 38

Student ticket = 17

Step-by-step explanation:

Let :

Adult ticket = x

Student ticket = y

x + y = 55 - - - - (1)

Cost per x = 3.75

Cost per y = 2

3.75x + 2y = 176.50 - - - (2)

From (1):

x = 55 - y

Put in (2)

3.75(55 - y) + 2y = 176.50

206.25 - 3.75y + 2y = 176.50

-1.75y = - 29.75

y = - 29.75 / - 1.75

y = 17

From :

x = 55 - y

x = 55 - 17

x = 38

A surveyor is estimating the distance across a river. The actual distance is 284.5 m. The surveyor's estimate is 300 m. Find the absolute error and the percent error of the surveyor's estimate. If necessary, round your answers to the nearest tenth.

(i) Absolute error = 15.5m

(ii) Percent error = 5.5%

Given:

Actual measurement of the distance = 284.5 m

Estimated measurement of the distance by the surveyor = 300 m

(i) The absolute error is the magnitude of the difference between the estimated value measured by the surveyor and the actual value of the distance across the river.

i.e

Absolute error = | estimated value - actual value |

Absolute error = | 300m - 284.5m | = 15.5m

(ii) The percent error (% error) is given by the ratio of the absolute error to the actual value then multiplied by 100%. i.e

% error = [tex]\frac{absoluteError}{actualValue}[/tex] x 100%

% error = [tex]\frac{15.5}{284.5}[/tex] x 100%

% error = 0.05448 x 100%

% error = 5.448%

% error = 5.5%  [to the nearest tenth]

=================================================

Work Shown:

S = sum of all interior angles of a polygon

S = 180(n-2)

2700 = 180(n-2)

180(n-2) = 2700

n-2 = 2700/180

n-2 = 15

n = 15+2

n = 17

There are 17 sides to this polygon.

-------------------------

Extra info (optional section):

We call this a 17-gon. Simply start with "n-gon" and replace n with 17.

You could also call it a heptadecagon

hepta = 7

deca = 10

so heptadeca means 17. Personally, I prefer 17-gon as the better name since it's easier to remember.

Answer:

good point I don't know that either

Given:

Line A goes through (0,y) and (-2,0).

Line B goes through (1,2) and (3,10).

To find:

The value of y for which the system of given linear equation (equation of line A and line B) has no solutions.

Solution:

Two linear equation has no solutions if they are parallel line.

Slope formula:

[tex]m=\dfrac{y_2-y_1}{x_2-x_1}[/tex]

We know that the slopes of two parallel lines are the same.

So, the given system of given linear equation has no solutions if

Slope of line A = Slope of line B

[tex]\dfrac{0-y}{-2-0}=\dfrac{10-2}{3-1}[/tex]

[tex]\dfrac{-y}{-2}=\dfrac{8}{2}[/tex]

[tex]\dfrac{y}{2}=4[/tex]

Multiply both sides by 2.

[tex]\dfrac{y}{2}\times 2=4\times 2[/tex]

[tex]y=8[/tex]

Therefore, the required value of y is 8.

Answer:  [tex]19x+11y \ge 4500[/tex]

=============================================

Explanation:

x = number of adults

y = number of students

The expression 19x represents the money from all the adults while 11y represents the money from all the students (since we get $19 per adult and $11 per student).

In total, the money collected is 19x+11y dollars.

We want this total to be $4500 or larger.

So that's how we get the final answer of [tex]19x+11y \ge 4500[/tex]

Answer:

8 miles

Step-by-step explanation:

I'm going to assume the question said that she "couldn't" repair the tire and was forced to walk back home, that makes more sense.

With that in mind:

She rode her bike 2 miles.

She walked 4 miles on the way there, and 6 miles on the way back.

You can deduce that it was a 6 mile walk back because of the 2 mile bike ride, then the 4 mile walk that it took to get there.

All in all that rounds out to 10 mile walking, and 2 mile biking. That is 8 miles more walking than biking.

Answer:

use the Desmos graphing calculator.  Type the first one in.  Then type your answer choices in.  See which lines are the same.

Step-by-step explanation:

Answer:

D

Step-by-step explanation:

Just simplify

Answer:

[tex]e^{\frac{1}{5}x} = \sum\limits^{\infty}_{k=0} \frac{1}{5}^k \cdot \frac{x^k}{k!}[/tex]

Step-by-step explanation:

Poorly formatted question.

The given parameters can be summarized as:

[tex]e^x = \sum\limits^{\infty}_{k=0} \frac{x^k}{k!}[/tex] ----- the series

Required

Determine [tex]e^\frac{1}{5}^x[/tex]

We have:

[tex]e^x = \sum\limits^{\infty}_{k=0} \frac{x^k}{k!}[/tex]

Substitute [tex]\frac{1}{5}x[/tex] for x

[tex]e^{\frac{1}{5}x} = \sum\limits^{\infty}_{k=0} \frac{(\frac{1}{5}x)^k}{k!}[/tex]

Split

[tex]e^{\frac{1}{5}x} = \sum\limits^{\infty}_{k=0} \frac{1}{5}^k \cdot \frac{x^k}{k!}[/tex]

Answer:

Oval frames = 17

Rectangular frames = 51

Step-by-step explanation:

Given that :

Paintings on wall are either oval or rectangular ;

Let :

Oval painting = x

Rectangular painting = y

According to the information given :

x + y = 68 - - (1)

Rectangular frames = 3 times oval frames

y = 3x - - - (2)

Put y = 3x in equation (1)

x + 3x = 68

4x = 68

x = 68/4

x = 17 frames

From :

x + y = 68

17 + y = 68

y = 68 - 17

y = 51

Oval frames = 17

Rectangular frames = 51