The time to complete an exam in a statistics class is a normal random variable with a mean of 50 minutes and a standard deviation of 10 minutes. What is the probability, given a class size of 30 students, the average time to complete the test is less than 48.5 minutes

Answer:

Step-by-step explanation:

1 - 8

2 - 14

3 - 22

Answer:

8,14,22

Step-by-step explanation:

Tn = n^2 +3n +4

n=1

    = 1^2 +3(1) +4

    = 1 +3+4

   = 8

n=2

    = 2^2 +3(2) +4

    = 4 +6+4

   = 14

n=3

    = 3^2 +3(3) +4

    = 9 +9+4

   = 22

Answer:

Pizza = 12.35

Chips = 2.75

Step-by-step explanation:

Let :

Pizza = x

chips = y

3x + 4y = 48.05 - - - (1)

5x + 2y = 67.25 - - - (2)

Multiply (1) by 5 and (2) by 3

15x + 20y = 240.25

15x + 6y = 201.75

Subtract :

20y - 6y = 240.25 - 201.75

14y = 38.50

y = 38.50/ 14

y = 2.75

Put y = 2.75 in (1)

3x + 4(2.75) = 48.05

3x + 11 = 48.05

3x = 48.05 - 11

3x = 37.05

x = 37.05 / 3

x = 12.35

Pizza = 12.35

Chips = 2.75

Step 1: Find the LCD (Least Common Denominator)

The LCD between 4 and 8 is 8. Therefore, if I change all of the fractions to have a denominator of 8, the problem is as such:

3/8 - 2/8 = ?

Step 2: Subtract

3/8 - 2/8 = 1/8

Hope this helps!

Answer:

[tex]\frac{1}{8}[/tex] (1/8)

Step-by-step explanation:

8·1=8

4·2=8

LCD=8

If the denominator is multiplied, the numerator also has to be multipled by the same value.

Hope this helped! Please mark brainliest :)

Answer:

the answer is y=2x+8

Step-by-step explanation:

Answer:

y = 3(3x - 1)

Step-by-step explanation:

Given the equation :

24x-12=4y-12x

Collect like terms

24x + 12x = 4y + 12

36x = 4y + 12

4y = 36x - 12

Divide through by 4

4y / 4 = 36x / 4 - 12 / 4

y = 9x - 3

y = 3(3x - 1)

Hence, y = 3(3x - 1)

Answer:

33km

Step-by-step explanation:

Let the distance traveled by bus be x, then distance traveled by train would be 2x

Therefore,

5 + x + 2x = 104

5 + 3x = 104

3x = 104 - 5

3x = 99

x = 33

Answer:

The insurance company should charge $1,873.5.

Step-by-step explanation:

Expected earnings:

1 - 0.99813 = 0.00187 probability of the company losing $1 million(if the client dies).

0.99813 probability of the company earning x(price of the insurance).

What premium would an insurance company charge to break even on a one-year $1 million term life insurance policy?

Break even means that the earnings are 0, so:

[tex]0.99813x - 0.00187(1000000) = 0[/tex]

[tex]0.99813x = 0.00187(1000000)[/tex]

[tex]x = \frac{0.00187(1000000)}{0.99813}[/tex]

[tex]x = 1873.5[/tex]

The insurance company should charge $1,873.5.

Answer:

hope it will be helpful to you.....

Answer:

L = 0.16 yd, W = 0.22 yd

Step-by-step explanation:

Dimensions of play ground 23/147 yd x 3/14 yd

reducing factor 2/147

Let the original length is L.

[tex]L - \frac{2L}{147} = \frac{23}{147}\\\\L\frac{143}{147} = \frac{23}{147}\\\\L=\frac{23}{143} yd[/tex]

L = 0.16 yd

Let the width is W.

[tex]W - \frac{2W}{147} = \frac{3}{14}\\\\W\frac{143}{147} = \frac{3}{14}\\\\W=0.22 yd[/tex]

Answer:

.3

Step-by-step explanation:

let x= P(f)

.65= .55+x-.2

P(F)=.3

Answer:

ai) 5pi

aii) 4.5pi

aiii) 4.1pi

b) 4pi

Step-by-step explanation:

a) Area of a circle is given by pi×r^2.

The average rate of change of the area of a circle from r=b to r=a is (pi×b^2-pi×a^2)/(b-a).

Let's simplify this.

Factor pi from the terms in the numerator:

pi(b^2-a^2)/(b-a)

Factor the difference of squares in the numerator:

pi(b-a)(b+a)/(b-a)

"Cancel" common factor (b-a):

pi(b+a).

So let's write a conclusive statement about what we just came up with:

The average rate of change of the area of a circle from r=b to r=a is pi(b+a).

i) from 2 to 3 the average rate of change is pi(2+3)=5pi.

ii) from 2 to 2.5 the average rate of change is pi(2+2.5)=4.5pi.

from 2 to 2.1 the average rate of change is pi(2+2.1)=4.1pi.

b) It looks like a good guess at the instantaneous rate of change is 4pi following what the average rate of change of the area approached in parts i) through iii) as we got closer to making the other number 2.

Let's confirm by differentiating and then plugging in 2 for r.

A=pi×r^2

A'=pi×2r

At r=2, we have A'=pi×2(2)=4pi. It has been confirmed.

9514 1404 393

Answer:

  50π cm²

Step-by-step explanation:

The radius of the larger circle is 10 cm, so its area is ...

  A = πr² = π(10 cm)² = 100π cm²

The area of each smaller circle is ...

  A = π(5 cm)² = 25π cm²

Then the shaded area is ...

  shaded = large circle - 2 × small circle

  shaded = 100π cm² - 2(25π cm²) = 50π cm²

Answer:

2.-P = 0.38

3.-P [ Lb | Wt ]  =  0.788

Step-by-step explanation:

1.-Probability of choosing any box is, 1/3. So the probability of choosing the lucky box is 1/3

Let´s say the lucky box is the number 2 box  ( that consideration does not in any way change the problem generality)

Then we have

p₁ probability of choosing box  1 is 1/3   p₁´ Probability of win ticket is  0.12

p₂ probability of choosing box 2 is 1/3  p₂´Probability of win ticket is  0.90

p₃ probability of choosing box 3 is 1/3  p₃´ Probability of win ticket is  0.12

Then

P (of choosing a winning ticket is) = p₁*p₁´ + p₂*p₂´ +  p₃*p₃´

P  =  1/3*0.12 + 1/3*0.9 + 1/3*0.12

P  =  0.04 + 0.3 + 0.04

P = 0.38

3.- if I draw a winning ticket what is the probability it came from Lucky box

According to Bayes theorem

P [ Lb | Wt ]  =   P(Lb) * P[ Wt|Lb]/ P(Wt)

P(Lb) = 1/3  =  0.33333

P[Wt|Lb]  = 0.9

P(Wt) = 0.38

Then By substitution

P [ Lb | Wt ]  =  0.333 *  0.9 / 0.38

P [ Lb | Wt ]  =  0.788

Answer:

[tex]option \: d \: 4.2 \times {10}^{ - 3} [/tex]

Step-by-step explanation:

Multiplication,

[tex] = 8.4 \times {10}^{ 8 } \times 5 \times {10}^{ - 11} \\ = 8.4 \times 5 \times {10}^{8 + ( - 11)} \\ = 4.2 \times {10}^{8 - 11} \\ = 4.2 \times {10}^{ - 3} [/tex]

The amount of water released from the sprinkler for 80 minutes is 200 L

What is an Equation?

Equations are mathematical statements with two algebraic expressions flanking the equals (=) sign on either side.

It demonstrates the equality of the relationship between the expressions printed on the left and right sides.

Coefficients, variables, operators, constants, terms, expressions, and the equal to sign are some of the components of an equation. The "=" sign and terms on both sides must always be present when writing an equation.

Given data ,

Let the amount of water from the sprinkler for 80 minutes be = A

Now , the value of A is given by the equation

A sprinkler releases water st a rate of 150 liters per hour

So , 60 minutes = 150 Liters of water

80 minutes = 1/60 hours

80 minutes = 1.333 hours

The amount of water released for 1.333 hours A = 150 x 1.333

On simplifying the equation , we get

The amount of water released for 1.333 hours A = 200 L

Therefore , the value of A is 200 L

To learn more about equations click :

https://brainly.com/question/19297665

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Answer:

Given Two equations :-

[tex]3x {}^{2} - 2 {y}^{2} = 57 .\: .\: .\: . \:(i) \\ - 2 {x}^{2} + 3 {y}^{2} = -23.\: .\: .\: . \:(ii)[/tex]

[tex](3x {}^{2} - 2 {y}^{2} = 57 ) \times 2 .\: .\: .\: . \:(i) \\ ( - 2 {x}^{2} + 3{y}^{2} = - 23) \times 3.\: .\: .\: . \:(ii)[/tex]

[tex]6x {}^{2} - 4 {y}^{2} =114 .\: .\: .\: . \:(i) \\ - 6 {x}^{2} + 9 {y}^{2} = - 69.\: .\: .\: . \:(ii)[/tex]

[tex]0 + 5 {y}^{2} = 45 \\ 5y {}^{2} = 45 [/tex]

[tex] {y}^{2} = 9[/tex]

[tex]y = + - 3[/tex]

3x²- 2×9 = 57

3x² - 18 = 57

3x² = 57 + 18

3x²= 75

x² = 25

x = ± 5

Answer:

[tex]{ \tt{ \frac{819}{13} = \frac{441}{h} }} \\ { \tt{h = \frac{(441 \times 13)}{819} }} \\ h = 7 \: hours[/tex]

Answer:

Step-by-step explanation:

Given right triangle with:

Use Pythagorean and solve for s:

Answer:

A) P(Type I error) = 0.045

B) P(Type II) error = 0.1

Step-by-step explanation:

We are told that the reliability of the test is 90% reliable.

Also, we are told that the probability that the test erroneously detects a lie even when the individual is actually telling the truth is 0.045.

Thus;

A) To calculate the probability of type I error:

From statistics, in this question we can say that the probability of a type I error is the probability that the test will erroneously detect a lie even though the individual is actually telling the truth. Thus;

Probability of (type I error) = P(rejecting true null) = 0.045

B) For probability of type II error, it is defined as the error where we accept a null hypothesis that is false. We can say that it produces a false negative and the formula is;

P(Type II) error = 1 - reliability

Reliability in the question is 0.90

Thus;

P(Type II) error = 1 - 0.9

P(Type II) error = 0.1

Answer:

Take the picture you uploaded.

Click the rotate button twice.

Done

9514 1404 393

Answer:

  7.51 m

Step-by-step explanation:

The equation matches that required for finding the length of a pendulum that has a period of 5.5 seconds. We can solve for L to find the length.

  [tex]5.5=2\pi\sqrt{\dfrac{L}{9.8}}\\\\\dfrac{5.5}{2\pi}=\sqrt{\dfrac{L}{9.8}}\\\\\left(\dfrac{5.5}{2\pi}\right)^2=\dfrac{L}{9.8}\\\\L=74.1125/\pi^2\approx7.509[/tex]

The length of a pendulum with period 5.5 seconds is about 7.51 meters.

Answer:

The length, L = 7.52 m.

Step-by-step explanation:

The given expression is

[tex]5.5= 2 \pi \sqrt\frac{L}{9.8}\\\\Sqauring on both the sides\\\\5.5 \times 5.5 = 4\pi^2 \times \frac{L}{9.8}\\\\L = 7.52 m[/tex]

The value of length is 7.52 m.

Answer:

(using the numbers youve prpvided) 3444544

Step-by-step explanation:

214 x 8 x 2012 = 3444544

Answer:

see the attachment

Step-by-step explanation:

Hope it helps you

Answer:

Tommy's age is 9 years old.

Timmy's age is 14 years old.

Step-by-step explanation:

Take Tommy's age to be x and Timmy's age to be x+5

x+x+5=23

2x+5=23

2x=23-5=18

x=18÷2=9

x+5=9+5=14

Answer:

Yes, it is appropriate

Step-by-step explanation:

Given

See attachment for pie chart

Required

Is the pie chart appropriate

The attached pie chart displays the distribution of each of the 4 genre. The partition occupied represents the measure of each genre.

Answer:

Smallest: 18° Middle: 54° Largest: 108°

Step-by-step explanation:

We can start by writing out what we know in a series of equations:

s= smallest angle, m= medium angle, L= largest angle.

Since the largest is 6 times the smallest we have:

L=6s

Since the middle is 3 times the smallest we have:

m=3s

Since the 3 interior angle measures of a triangle always must equal 180°, we have:

s+m+L=180

Then we plug in our L and m into the third equation:

s+3s+6s=180

Combining like terms and solving:

10s=180

s=18

Then we plug in 18 for s into the first 2 equations to get:

L= 6* 18

L= 108

and

m= 3* 18

m= 54

So s= 18, m= 54, and L=108.

To check the answer we can:

Step-by-step explanation:

For an equation of form Ax + By = C, we are given A, B, and C.

The x intercept is when the line/equation is on the x axis, or when y=0.

Therefore, if we plug y=0 into the equation Ax+By=C, and anything multiplied by 0 is equal to 0, we can say that

Ax + 0 = C

Ax = C

divide both sides by A

x  = C/A

Therefore, the x intercept is equal to C/A

Similarly, for the y intercept, or when the line is on the y axis (or when x=0), we have

A*0 + By = C

By = C

divide both sides by B

y= C/B at the y intercept

Answer:

Step-by-step explanation:

[tex]\frac{tan^2t}{sint}=\frac{tan t\times tant}{sin t} =\frac{tan t}{sint} \times \frac{sin t}{cos t} =\frac{tan t}{cos t} =tan t ~sec t[/tex]

Answer:

scale factor 5:2

x= 27.5

y=12

z=7.5

Step-by-step explanation: