A physical fitness association is including the mile run in its secondary-school fitness test. The time for this event for boys in secondary school is known to possess a normal distribution with a mean of 460 seconds and a standard deviation of 40 seconds. Find the probability that a randomly selected boy in secondary school can run the mile in less than 368 seconds.

Answer:

87°

Step-by-step explanation:

In the given figure, a quadrilateral is inscribed in a circle. Therefore, it is a cyclic quadrilateral.

Opposite angles of a cyclic quadrilateral are supplementary.

[tex] \therefore \: z + 93 \degree = 180 \degree \\ \therefore \: z = 180 \degree - 93 \degree \\ \huge \red{ \boxed{\therefore \: z = 87 \degree}}[/tex]

Answer:

-3

Step-by-step explanation:

Answer: choice B

Step-by-step explanation:

The graph of y=-3x^n is the reflection of the graph of y=3x^n about the x-axis.

Answer: B

Step-by-step explanation:

Answer:

18 + 81 = 9(x² + 6x + 9)

11 = (x + 3)²

When we are completing the square, we are going to move the value of c across the equals.  We will do that by adding, and end up with

18=9(x²+6x)

We take the value of b (the coefficient of x), divide it by 2 and square it:

(6/2)²=3²=9

This is the value that completes the square.  However, since the entire square is multiplied by 9, this value must be multiplied by 9 before we can add it across the equals:

18+9(9) = 9(x²+6x+9)

18+81=9(x²+6x+9)

99=9(x²+6x+9)

Dividing both sides by 9, we have:

11=x²+6x+9

11=(x+3)²

Answer:

18 + 81 = 9(x2 + 6x + 9) and 11 = (x + 3)2

Step-by-step explanation:

EDG

Answer:

In the figure ∠ABO and ∠BCO have measures equal to 35°.

Step-by-step explanation:

Measure of arc AD = 180-measure of arc CD= 180-125 =55

m<AOB= 55 ( measure of central angle is equal to intercepted arc)

<OAB= 90 degrees (Tangent makes an angle of 90 degrees with the radius)

In triangle AOB ,

< AB0 = 180-(90+55)= 35 degrees( angle sum property of triangle)

In triange BOC ,< BOC=125 ,

m<, BCO=35 degrees

Answer:

∠ABO and ∠BCO

Step-by-step explanation:

Answer:

50π cm²

Step-by-step explanation:

In this case we have that the area of the boomerang has been the area of the largest semicircle minus the area of the smaller semicircles.

We know that the radius is half the diameter:

r = d / 2 = 20/2

r = 10

Now we have to:

Alargest = π · r²

Alargest = π · (10 cm) ²

Alargest = 100π cm²

Asmaller = π · r²

Asmaller = π · (5 cm) ²

Asmaller = 25π cm²

Finally, the boomerang area has been:

Aboomerang = 100π cm² - 2 · (25π cm²)

Aboomerang = 50π cm²

Answer:

b = -18

Step-by-step explanation:

(3 + 4i) (-3-2i)

When we foil:

-9 + -6i + -12i + -8i^2

-8i^2 = +8

Combine like terms:

-1 + -18i

Answer:

z(65) = (65-64.2)/[2.81/sqrt(60)] = 0.8/(0.3279)

Step-by-step explanation:

Using the normal probability distribution and the central limit theorem, it is found that there is a 0.0154 = 1.54% probability that the mean height for the sample is greater than 65 ​inches.

In a normal distribution with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the z-score of a measure X is given by:

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

In this problem:

The probability that the mean height for the sample is greater than 65 ​inches is 1 subtracted by the p-value of Z when X = 65, thus:

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

By the Central Limit Theorem

[tex]Z = \frac{X - \mu}{\frac{\sigma}{\sqrt{n}}}[/tex]

[tex]Z = \frac{65 - 64.3}{\frac{2.81}{\sqrt{75}}}[/tex]

[tex]Z = 2.16[/tex]

[tex]Z = 2.16[/tex] has a p-value of 0.9846.

1 - 0.9846 = 0.0154

0.0154 = 1.54% probability that the mean height for the sample is greater than 65 ​inches.

A similar problem is given at https://brainly.com/question/24663213

Answer:

b. The engineer who weighed the rod 25 times.

Step-by-step explanation:

Hello!

Full text:

Length of a rod: Engineers on the Bay Bridge are measuring tower rods to find out if any rods have been corroded from salt water. There are rods on the east and west sides of the bridge span. One engineer plans to measure the length of an eastern rod 25 times and then calculate the average of the 25 measurements to estimate the true length of the eastern rod. A different engineer plans to measure the length of a western rod 20 times and then calculate the average of the 20 measurements to estimate the true length of the western rod.

Suppose the engineers construct a 90% confidence interval for the true length of their rods. Whose interval do you expect to be more precise (narrower)?

a. Both confidence intervals would be equally precise.

b. The engineer who weighed the rod 25 times.

c. The engineer who weighed the rod 20 times.

X₁: Length of an eastern rod of the Bay Bridge

n₁= 25

X₂: Length of a western rod of the Bay Bridge

n₂= 20

Both Engineers will use their samples to estimate the population average length of the rods using a 90% CI.

Assuming the standard normal distribution, the confidence interval will be centered in the estimated mean.

X[bar] ± [tex]Z_{1-\alpha /2}[/tex]*(σ/√n)

And the width is determined by the semi amplitude:

↓d= [tex]Z_{1-\alpha /2}[/tex]*(σ/√↑n)

As you can see the sample size has an indirect relationship with the semi amplitude of the interval. This means, when the sample size increases, the semi amplitude decreases, and if the sample size decreases, the semi amplitude increases. Naturally this is leaving all other elements of the equation constant, this means, using the same confidence level and the same population standard deviation.

Since the first engineer took the larger sample, he's confidence interval will be narrower and more accurate.

Hope this helps!

Answer:

a) H0: [tex]\sigma = 1.34[/tex]

H1: [tex]\sigma \neq 1.34[/tex]

b) [tex] df = n-1= 10-1=9[/tex]

And the critical values with [tex]\alpha/2=0.005[/tex] on each tail are:

[tex] \chi_{\alpha/2}= 1.735, \chi_{1-\alpha/2}= 23.589[/tex]

c) [tex] t=(10-1) [\frac{1.186}{1.34}]^2 =7.05[/tex]

d) For this case since the critical value is not higher or lower than the critical values we have enough evidence to FAIL to reject the null hypothesis and we can conclude that the true deviation is not significantly different from 1.34

Step-by-step explanation:

Information provided

n = 10 sample size

s= 1.186 the sample deviation

[tex]\sigma_o =1.34[/tex] the value that we want to test

[tex]p_v [/tex] represent the p value for the test

t represent the statistic  (chi square test)

[tex]\alpha=0.01[/tex] significance level

Part a

On this case we want to test if the true deviation is 1,34 or no, so the system of hypothesis are:

H0: [tex]\sigma = 1.34[/tex]

H1: [tex]\sigma \neq 1.34[/tex]

The statistic is given by:

[tex] t=(n-1) [\frac{s}{\sigma_o}]^2 [/tex]

Part b

The degrees of freedom are given by:

[tex] df = n-1= 10-1=9[/tex]

And the critical values with [tex]\alpha/2=0.005[/tex] on each tail are:

[tex] \chi_{\alpha/2}= 1.735, \chi_{1-\alpha/2}= 23.589[/tex]

Part c

Replacing the info we got:

[tex] t=(10-1) [\frac{1.186}{1.34}]^2 =7.05[/tex]

Part d

For this case since the critical value is not higher or lower than the critical values we have enough evidence to FAIL to reject the null hypothesis and we can conclude that the true deviation is not significantly different from 1.34

Answer:

8x/5

There’s a 1 in front of the x also remember to always simplify

3/5x + 1x

Answer:8x/5

Step-by-step explanation:

Answer:

D is 10

b/12

Step-by-step explanation:

Answer:

[tex]\log_84+\log_8a+\log_8(b-4)-4\log_8c[/tex].

Step-by-step explanation:

The given expression is

[tex]\log_84a\left(\dfrac{b-4}{c^4}\right)[/tex]

Using the properties of logarithm, we get

[tex]\log_84+\log_8a+\log_8\left(\dfrac{b-4}{c^4}\right)[/tex]     [tex][\because \log_a mn=\log_a m+\log_a n][/tex]

[tex]\log_84+\log_8a+\log_8(b-4)-\log_8c^4[/tex]     [tex][\because \log_a \frac{m}{n}=\log_a m-\log_a n][/tex]

[tex]\log_84+\log_8a+\log_8(b-4)-4\log_8c[/tex]     [tex][\because \log_a x^n =n\log_a x][/tex]

Therefore, the required expression is [tex]\log_84+\log_8a+\log_8(b-4)-4\log_8c[/tex].

Answer:

B on edge

Step-by-step explanation:

Answer:

30%

Step-by-step explanation:

fat ÷ total

15 ÷ 50

.3

30%

Answer:

30%

Step-by-step explanation:

To find the percent from fat, take the calories from fat and divide by the total

15/50

.3

Multiply by 100%

30%

Answer:

#1

Step-by-step explanation:

The four yellow boxes represent x so together they are 4 * x or 4x. The blue boxes seem to represent -1 and since there are three of them together they are -1 * 3 = -3. 4x + (-3) = 4x - 3.

Answer:

Part a

Null hypothesis: [tex] \mu = 69.3[/tex]

Alternative hypothesis: [tex]\mu \neq 69.3[/tex]

Part b

[tex] z = \frac{69.8- 69.3}{\frac{11.2}{\sqrt{140}}}= 0.528[/tex]

Step-by-step explanation:

For this case we have the following info given :

[tex] \bar X = 69.8[/tex] the sample mean

[tex] n= 140[/tex] represent the sample size

[tex] s = 11.2[/tex] represent the standard deviation

Part a

And we want to test if the true mean is equal to 69.3 so then the system of hypothesis:

Null hypothesis: [tex] \mu = 69.3[/tex]

Alternative hypothesis: [tex]\mu \neq 69.3[/tex]

Part b: Find the statistic

The statistic is given by:

[tex] z= \frac{\bar X - \mu}{\frac{\sigma}{\sqrt{n}}}[/tex]

And replacing the info we got:

[tex] z = \frac{69.8- 69.3}{\frac{11.2}{\sqrt{140}}}= 0.528[/tex]

Answer:

15%

Step-by-step explanation:

Is means equals and of means multiply

60 = P * 400

Divide each side by 400

60/400 = P

.15 = P

Change to percent form

15%  is the percent

Answer:

the answer to the question you've asked is 15

Answer:

[tex]\mathbf{\dfrac{e^{2t}}{36} + \dfrac{e^{3t}}{18} + \dfrac{e^{4t}}{12} +\dfrac{e^{5t}}{9} + \dfrac{5e^{6t}}{36} + \dfrac{7e^{7t}}{6} + \dfrac{5e^{8t}}{36} + \dfrac{e^{9t}}{9} + \dfrac{e^{10t}}{12} + \dfrac{e^{11t}}{18} + \dfrac{e^{12t}}{36} }[/tex]

Step-by-step explanation:

The objective is to find the moment generating  function of  [tex]M_{X+Y}(t) \ of \ X+Y[/tex].

We are being informed that the fair die is rolled twice;

So; X to be the value for the  first roll

Y to be the value of the second roll

The outcomes  of X are:  X = {1,2,3,4,5,6}

Where ;

[tex]P (X=x) = \dfrac{1}{6}[/tex]

The outcomes  of Y are:  y = {1,2,3,4,5,6}

Where ;

[tex]P (Y=y) = \dfrac{1}{6}[/tex]

The outcome of Z = X+Y

[tex]= \left[\begin{array}{cccccc}(1,1)&(1,2)&(1,3)&(1,4)&(1,5)&(1,6)\\ (2,1)&(2,2)&(2,3)&(2,4)&(2,5)&(2,6)\\ (3,1)&(3,2)&(3,3)&(3,4)&(3,5)&(3,6) \\ (4,1)&(4,2)&(4,3)&(4,4)&(4,5)&(4,6) \\ (5,1)&(5,2)&(5,3)&(5,4)&(5,5)&(5,6) \\ (6,1)&(6,2)&(6,3)&(6,4)&(6,5)&(6,6) \end{array}\right][/tex]

= [2,3,4,5,6,7,8,9,10,11,12]

Here;

[tex]P (Z=z) = \dfrac{1}{36}[/tex]

∴ the moment generating function [tex]M_{X+Y}(t) \ of \ X+Y[/tex]is as follows:

[tex]M_{X+Y}(t) \ of \ X+Y[/tex] = [tex]E(e^{t(X+Y)}) = E(e^{tz})[/tex]

⇒ [tex]\sum \limits^{12}_ {z=2 } et ^z \ P(Z=z)[/tex]

= [tex]\mathbf{\dfrac{e^{2t}}{36} + \dfrac{e^{3t}}{18} + \dfrac{e^{4t}}{12} +\dfrac{e^{5t}}{9} + \dfrac{5e^{6t}}{36} + \dfrac{7e^{7t}}{6} + \dfrac{5e^{8t}}{36} + \dfrac{e^{9t}}{9} + \dfrac{e^{10t}}{12} + \dfrac{e^{11t}}{18} + \dfrac{e^{12t}}{36} }[/tex]

Answer:

Dear Laura Ramirez

Answer to your query is provided below

Option D is correct.

Reason - Because of Hinge and Converse of Hinge theorem

Answer:

The answer is 508

Step-by-step explanation:

Solution

First of all, the proportion of B is exceeds 0.5 in total.

Now,

To find the total of A it we have A =314 +512 = 826

The number of employed that choose B = 356

For us to have the proportion of B to be higher than the 0.5, the unemployed B from what is shown here should exceed the difference between total A and B employed

what this suggest is that the employed B is greater than 826-356 = 470

So,

The respondent that are unemployed that choose B  must be greater than 470

Thus,

We recall that the B proportion among the unemployed respondent is lesser than .50

Thus suggests that the respondent that are unemployed who choose be is lesser than 512

The conditions becomes

470 lesser than the number of unemployed respondents who selected B lesser than 512

Hence  the needed number of the number of unemployed respondents who chose B should be between 470 and 512

So, possible answer here is 508.

Answer:

The perimeter is

Step-by-step explanation:

perimeter is the whole distance you will go around the shape

Perimeter= 19 +3+(19-5)+(8-3)+5+8

= 19+3+14+5+5+8

= 54

For area, cut the triangle into small and big rectangle

Area = 19 * 3+ (8-3) * 5

= 57 + 25

= 82

Answer:

-5.7° C

Step-by-step explanation:

-2.7 °C (degrees Celsius) - 3 °C (degrees Celsius) = -5.7° C

Answer: radius and height

Step-by-step explanation:

Radius is the distance between the center of the circle to its boundary.

Height is the length of the figure from top to bottom.

Given statement : A cylinder with height of 42 millimeters and radius of 12 millimeters.

That clearly means that the cylinder is having radius of 12 millimeters i.e. 12 is representing the measure of the radius of the cylinder.

And Similarly, 42 is representing the measure of the height of the cylinder.

Hence, the 2 and 42 describe the radius and height respectively of the cylinder.

Answer:

radius and height

Step-by-step explanation:

i just took the test edge 2020. rate me 5 stars!

Answer:

Both F and Z have symmetry.

Answer:

  44x +56y = 95

Step-by-step explanation:

To write the equation of the perpendicular bisector, we need to know the midpoint and we need to know the differences of the coordinates.

The midpoint is the average of the coordinate values:

  ((-2.5, -2) +(3, 5))/2 = (0.5, 3)/2 = (0.25, 1.5) = (h, k)

The differences of the coordinates are ...

  (3, 5) -(-2.5, -2) = (3 -(-2.5), 5 -(-2)) = (5.5, 7) = (Δx, Δy)

Then the perpendicular bisector equation can be written ...

  Δx(x -h) +Δy(y -k) = 0

  5.5(x -0.25) +7(y -1.5) = 0

  5.5x -1.375 +7y -10.5 = 0

Multiplying by 8 and subtracting the constant, we get ...

  44x +56y = 95 . . . . equation of the perpendicular bisector

Answer:

1.08

Step-by-step explanation:

If Romeo earns 8% more than Juliet,

Example?

If Juliet earns $80

80x8% = 6.40  So his pay would be 80 + 6.40

If you times 80 by 1.08 (this would also be 108%) you would get $86.40

Answer:

1674 ft²

Step-by-step explanation:

Area S = 65*30

Area A = (65 - x)(30 - x) = (65 - 3)(30 - 3) = 62*27= 1674 ft²

Answer:

6

Step-by-step explanation:

Let's call the number of pairs of socks he buys s.

[tex]12.50+2.50s=27.50[/tex]

Subtract 12.50 from both sides:

[tex]2.50s=15[/tex]

Divide both sides by 2.5 to isolate s:

[tex]s=6[/tex]

Hope this helps!

Answer:

4cos=2X

X=3-4COS

X=-1