Two students, A and B, are working independently on homework (not necessarily for the same class). Student A takes X = Exp(1) hours to finish his or her homework, while B takes Y = Exp(2) hours. (a) Find the CDF of X/Y , the ratio of their problem-solving times. (b) Find the probability that A finishes his or her homework before B does.

Answer:

true

Step-by-step explanation:

just took test

Answer:

The correct answer to the following question will be Option A.

Step-by-step explanation:

Other given choices are not related to the given circumstances. So that option A seems to be the appropriate choice.

Answer:

[tex]P(X>72)=P(\frac{X-\mu}{\sigma}>\frac{72-\mu}{\sigma})=P(Z>\frac{72-70}{4})=P(z>0.5)[/tex]

And we can find this probability using the complement rule and the normal standard table:

[tex]P(z>0.5)=1-P(z<0.5)= 1- 0.69146= 0.3085[/tex]

And the best solution would be:

c. 0.3085

Step-by-step explanation:

For this case we can convert all the values to inches in order to standardize the solution:

[tex] 5ft * \frac{12 in}{1ft}= 60 in[/tex]

[tex] 6ft * \frac{12 in}{1ft}= 72 in[/tex]

Let X the random variable that represent the heights of US mens, and for this case we know the distribution for X is given by:

[tex]X \sim N(70,4)[/tex]  

Where [tex]\mu=70[/tex] and [tex]\sigma=4[/tex]

We are interested on this probability

[tex]P(X>72)[/tex]

We can use the z score formula given by:

[tex]z=\frac{x-\mu}{\sigma}[/tex]

Using this formula we got:

[tex]P(X>72)=P(\frac{X-\mu}{\sigma}>\frac{72-\mu}{\sigma})=P(Z>\frac{72-70}{4})=P(z>0.5)[/tex]

And we can find this probability using the complement rule and the normal standard table:

[tex]P(z>0.5)=1-P(z<0.5)= 1- 0.69146= 0.3085[/tex]

And the best solution would be:

c. 0.3085

Using the normal distribution, it is found that the probability that a randomly chosen American man is taller than 6 feet (72 inches) is equal to:

c. 0.3085

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 of being taller than 72 inches is 1 subtracted by the p-value of Z when X = 72, thus:

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

[tex]Z = \frac{72 - 70}{4}[/tex]

[tex]Z = 0.5[/tex]

[tex]Z = 0.5[/tex] has a p-value of 0.6915.

1 - 0.6915 = 0.3085

Thus, option c.

A similar problem is given at https://brainly.com/question/24855678

Answer:

  1) h = -1/2t^2 +10t

  2) h = -1/2(t -10)^2 +72

  3) domain: [0, 20]; range: [0, 50]

Step-by-step explanation:

1.) I find it easiest to start with the vertex form when the vertex is given. The equation of the presumed parabolic path for Firework 1 is ...

  h = a(t -10)^2 +50

To find the value of "a", we must use another point on the graph. (0, 0) works nicely:

  0 = a(0 -10)^2 +50

  -100a = 50 . . . . . . subtract 100a

  a = -1/2 . . . . . . . . . divide by -100

Then the standard-form equation is ...

  h = (-1/2)(t^2 -20t +100) +50

  h = -1/2t^2 +10t

__

2.) The path of Firework 2 is translated upward by 22 units from that of Firework 1.

  h = -1/2(t -10)^2 +72

__

3.) The horizontal extent of the graph for Firework 1 is ...

  domain: 0 ≤ t ≤ 20

The vertical extent of the graph for Firework 1 is ...

  range: 0 ≤ h ≤ 50

Answer:

D

Step-by-step explanation:

2² + 6² = x²

4 + 36 = x²

40 = x²

x = 2√10

Answer:

21

Step-by-step explanation:

Similar triangles. MNL is just ABC but 3/4 the size.

x = 8*3/4 = 6

perimeter woudl be 6+6+9 = 21

Answer:

25% decrease

Step-by-step explanation:

Take the original price and subtract the new price

450-337.50 =112.50

Divide by the original price

112.50/450=.25

Multiply by 100% to change to percent form

25%

Step-by-step explanation:

I hope it's correct... Hope this is what you want

Answer:

There were 300 students

Step-by-step explanation:

Original * 30 = increase

Add the increase to get the new number

original + increase = 308

original + original*30% = 390

Factor out original number

original ( 1+30%) = 390

Change to decimal form

original ( 1+.30) = 390

original ( 1.30) = 390

Divide by 1.3

original = 390/1.3

             =300

Answer:

0-19: Make it 4 units tall

20-39: Make it 2 units tall

40-59: Make it 5 units tall

60-79: Make it 3 units tall

80-99: Make it 1 unit tall

Step-by-step explanation:

0-19: 4, 6, 19, 19 (4 numbers)

20-39: 29, 38 (2 numbers)

40-59: 40, 41, 41, 57, 58 (5 numbers)

60-79: 62, 66, 73 (3 numbers)

80-99: 87 (1 number)

Answer:

Since the z score for the male is z=-2.1589 and the z score for the female is z=-2.6844​, the female has the weight that is more extreme.

Step-by-step explanation:

To find the z score, we use the following equation:

[tex]z=\frac{x-m}{s}[/tex]

Where m is the mean and s is the standard deviation.

So, the z score for a male who weighs 1700 g is:

[tex]z=\frac{1700-3259.6}{722.4}=-2.1589[/tex]

At the same way, the z score for a female who weighs 1700 g is:

[tex]z=\frac{1700-3031.2}{495.9}=-2.6844[/tex]

Finally, -2.6844 is farther from zero than -2.1589, so the female has the weight that is more extreme.

Answer:

D . P(x)=-0.5

Step-by-step explanation:

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Answer:

0.1800 to 4 places of decimals.

Step-by-step explanation:

Using the Binomial formula

Probability = 10C5* (0.95)^95 * (0.05)^5

= 100! / 95!*5! *  (0.95)^95 * (0.05)^5

= 0.1800178.

:

Answer:

the answer is the arrow going to the right because its not a negative number and a closed circle

Step-by-step explanation:

so that means that 2x is at LEASt more than -4 opposed to this sign> wich just means greater than

because when you work with variables you usually cannot find the exact amount especially when you are rounding so you know that its biigger than no less than or at least -4

the answer is the arrow going to the right because its not a negative number and a closed circle

please please mark as brainliest

Answer:

5.5 hours

Step-by-step explanation:

Let the no. of hours worked in morning by Pat = x hours

given that "She worked 3 hours more in the after-

noon than she worked in the morning"

No. of hours worked in Afternoon by Pat = x + 3  hours

Total hours worked in the day = x + x+3 = 2x +3 hours  (1)

It is given that Pat worked for 8 hours that day (2)

thus, using 1 and 2 we have

2x +3  =  8

=>2x = 8 - 3 = 5

=> x = 5/2 = 2.5

no. of hours worked in morning by Pat = x hours = 2.5 hours

No. of hours worked in Afternoon by Pat = x + 3  hours = 2.5 + 3 hours

 No. of hours worked in Afternoon by Pat = 5.5 hours --- Answer.

Answer:

10

Step-by-step explanation:

Answer:

10

Step-by-step explanation:

Square root is finding what number times what gets your goal.

10 x 10 = 100 so 100 squared is 10.

5 x 5 = 25 so 25 squared is 5.

4 x 4 = 16 so 15 squared is 4.

You get it? :)

Have a nice day!

Answer:

900000cubic feet

Step-by-step explanation:

capacity of dump hole= 250*120*30

= 900000cubic feet

Answer:

The sample size required is 289.

Step-by-step explanation:

Let p be population proportion of people that would buy the product.

It is provided that the nationwide poll on this type of product and price was run earlier this year, with percentages running from 75% to 80%.

Assume that the sample proportion of people that would buy the product is, [tex]\hat p=0.75[/tex].

A 95% Confidence Interval is to be constructed with a margin of error of 5%.

We need to determine the sample size required for the 95% Confidence Interval to be within 5% of the actual value.

The formula to compute the margin of error for a (1 - α)% confidence interval of population proportion is:

[tex]MOE=z_{\alpha/2}\times\sqrt{\frac{\hat p(1-\hat p)}{n}}[/tex]

The critical value of z for 95% confidence interval is,

z = 1.96.

Compute the sample size required as follows:

[tex]MOE=z_{\alpha/2}\times\sqrt{\frac{\hat p(1-\hat p)}{n}}[/tex]

      [tex]n=[\frac{z_{\alpha/2}\ \sqrt{\hat p(1-\hat p)} }{MOE}]^{2}[/tex]

         [tex]=[\frac{1.96\cdot \sqrt{0.75(1-0.75)} }{0.05}]^{2}\\\\=(16.9741)^{2}\\\\=288.12007081\\\\\approx 289[/tex]

Thus, the sample size required is 289.

Answer:

x = 0.375

Step-by-step explanation:

Step 1: Simplify both sides of the equation

8x − 3 + 14 = 24x + 5

(8x) + (−3 + 14) = 24x + 5

8x + 11 = 24x + 5

- 24

-16x + 11 = 5

-11

-16x = -6

-16x/-16 = -6/-16

x = 3/8

x = 0.375

Answer:

A, W, X, Y, M, O, T, U, V, C, D

Step-by-step explanation:

If you put a line through the middle, then the left and the right side will look the same

The number of race times recorded as portrayed by the number of data points is seven(7).

From the task content;

Additionally, it follows from the task content that the times recorded were; 6.8,7.3,7.1 ,7.0,7.2,7.3 and 7.0.

On this note, the number of race times recorded as portrayed by the number of data points is seven(7).

Read more on data points;

https://brainly.com/question/3514929

Answer:

x^2 + y^2 = 25

Step-by-step explanation:

x = 5 cos t

            cos t = x/5

y = 5 sin t

           sin t = y/5

cos^2 t + sin^2 t = 1

(x/5)^2 + (y/5)^2  = 1

x^2/25 + y^2/25 = 1

(x^2 + y^2)/25 =1

x^2 + y^2 = 25

Answer:

D. 7017

Step-by-step explanation:

if 24 is the first term, find 7x999, or 7x1000-7 and add 24

however a better way would be to use the formula

value=a+(n-1)d

a = the first term in the sequence (24)

n     =     the amount of terms you need (1000)

d = the common difference between terms (7)

Answer:

Vector is equal to vector b. For two vectors to be equal, they must have both the magnitude and the directions equal.

Step-by-step explanation:

Answer:

B. F(x) = 3(x - 2)² - 2

Step-by-step explanation:

→The function F(x) narrowed, meaning the absolute value being multiplied to the function is greater than 1.

→The function F(x) flipped over the x-axis, this means that the number being multiplied has to be a negative.

→The function F(x) shifted to the left 2 units, this means there needs to be a 2 being added.

→The function F(x) shifted downwards 2 units, meaning there needs to be a 2 being subtracted from the whole function.

This gives us the correct answer of "B. F(x) = 3(x - 2)² - 2."

Answer:

[tex] P(t) = A (1+r)^t [/tex]

Where P represent the population after t days. a the initial amount on this case 6 and r the growth factor rate of 0.7781. so then our model would be given by:

[tex] P(t)= 6(1.7781)^t [/tex]

And replacing t=4 we got:

[tex] P(4) = 6(1.7781)^4 =59.975 \approx 60[/tex]

So then after 4 days we would expect about 60 protzoa

Step-by-step explanation:

For this case we can use the following function to model the population of protzoa:

[tex] P(t) = A (1+r)^t [/tex]

Where P represent the population after t days. a the initial amount on this case 6 and r the growth factor rate of 0.7781. so then our model would be given by:

[tex] P(t)= 6(1.7781)^t [/tex]

And replacing t=4 we got:

[tex] P(4) = 6(1.7781)^4 =59.975 \approx 60[/tex]

So then after 4 days we would expect about 60 protzoa

Answer:

(a) Roughly 68% of vehicle speeds were between 27 and 57 mph.

(b) Roughly 16% of vehicle speeds exceeded 57 mph.

Step-by-step explanation:

We are given that in a study investigating the effect of car speed on accident severity, 5000 reports of fatal automobile accidents were examined.

For these 5000 accidents, the average speed was 42 mph and the standard deviation was 15 mph.

Let X = vehicle speed at impact

SO, X ~ Normal([tex](\mu=42,\sigma^{2} = 15^{2}[/tex])

Here, [tex]\mu[/tex] = population average speed = 42 mph

         [tex]\sigma[/tex] = standard deviation = 15 mph

Since, the distribution is approximately normal; so the 68-95-99.7 empirical rule states that;

(a) Since, it is stated above that 68% of the data values lies within one standard deviation points, that means;

68% data values will lie between [ [tex]\mu-\sigma , \mu+\sigma[/tex] ] , i.e;

        [ [tex]\mu-\sigma , \mu+\sigma[/tex] ]  =  [42 + 15 , 42 - 15]

                                 =  [57 , 27]

So, it means that roughly 68% of vehicle speeds were between 27 and 57 mph.

(b) We have observed above that roughly 68% of vehicle speeds were between 27 and 57 mph which leads us to the conclusion that (100% - 68% = 32%) of the data values will be outside this range.

It is stated that of this 32%, half of the data values will be less than 27 mph and half of the data values will be more than 57 mph.

This means that roughly 16% of vehicle speeds exceeded 57 mph.

Answer: a) 39.5%

Step-by-step explanation:

For random selections, we assume that all the dogs have the same probability of being selected.

In this case, the probability will be equal to the number of golden retrievers divided the total number of dogs.

We have 58 golden retrievers, and the total number of dogs is:

31 + 58 +20 + 38 = 147

Then the probability is:

P = 58/147 = 0.395

If we multiply it by 100%, we obtain the percentage form:

0.395*100% = 39.5%

So the correct option is a.

Answer:

77

Step-by-step explanation:

80*0.2 + 84*0.3 + 74*0.4 + 60*0.1 = 76.8 = 77