Derivative of Y=cos^2(3x)

The capacity of an elevator is 12 people or 2088 pounds. the capacity will be exceeded if 12 people have weights with a mean gre

boyakko [2]

suppose the people have weights that are normally distributed with a mean of 177 lb and a standard deviation of 26 lb.

Find the probability that if a person is randomly selected, his weight will be greater than 174 pounds?

Assume that weights of people are normally distributed with a mean of 177 lb and a standard deviation of 26 lb.

Mean = 177

standard deviation = 26

We find z-score using given mean and standard deviation

z = $\frac{x-mean}{standard deviation}$

= $\frac{174-177}{26}$

=-0.11538

Probability (z>-0.11538) = 1 - 0.4562 (use normal distribution table)

= 0.5438

P(weight will be greater than 174 lb) = 0.5438

8 0

3 years ago

The cost of 5 books is 71$ . What is the cost of each book

Alla [95]

$14.20 is the cost of each book

3 0

3 years ago

Read 2 more answers

Urgent answer needed pls

worty [1.4K]

Answer:

48 cm²

Step-by-step explanation:

PTRS is parallelogram with the base length= 8cm and the height as same as the height of ∆SUR.

the height = 2×24/8 = 6cm

so, the area of PTRS= 8×6 = 48 cm²

6 0

2 years ago

The U.S. and many other countries have recently tightened airport security. A sociologist is interested in estimating the propor

melisa1 [442]

Answer:

0.0073 < 0.05, which means that we reject the null hypothesis and conclude that the true proportion of interest is higher than 0.7.

Step-by-step explanation:

Conduct a test to determine whether the true proportion of interest is higher than 0.7.

This means that the null hypothesis is: $H_{0}: p = 0.7$

And the alternate hypothesis is: $H_{a}: p > 0.7$

The test statistic is:

$z = \frac{X - \mu}{\frac{\sigma}{\sqrt{n}}}$

In which X is the sample mean, $\mu$ is the value tested at the null hypothesis, $\sigma$ is the standard deviation and n is the size of the sample.

0.7 is tested at the null hypothesis:

This means that $\mu = 0.7, \sigma = \sqrt{0.7*0.3}$

The sociologist found that 375 of the 500 travelers randomly selected and interviewed indicated that the airports were safe.

This means that $n = 500, X = \frac{375}{500} = 0.75$

Value of the z-statistic:

$z = \frac{X - \mu}{\frac{\sigma}{\sqrt{n}}}$

$z = \frac{0.75 - 0.7}{\frac{\sqrt{0.7*0.3}}{\sqrt{350}}}$

$z = 2.44$

P-value of the test:

Probability of z being larger than 2.44, that is, a proportion larger than 0.75.

This is, looking at the z-table, 1 subtracted by the pvalue of Z = 2.44. S

Z = 2.44 has a pvalue of 0.9927

1 - 0.9927 = 0.0073

0.0073 < 0.05, which means that we reject the null hypothesis and conclude that the true proportion of interest is higher than 0.7.

8 0

2 years ago

The sum of four consecutive odd integers is -72. Write an equation to model this situation, and ind the values of the four integ

Nutka1998 [239]

Answer:

equation: (x-3) +(x-1) +(x+1) +(x+3) = -72
values: -21, -19, -17, -15

Step-by-step explanation:

When dealing with consecutive integers, it often simplifies the problem to work with their average value. We know the average value of the integers in this problem is the even integer between the middle two. We can call it x, and write the equation ...

(x-3) +(x-1) +(x+1) +(x+3) = -72

This simplifies to ...

4x = -72 . . . . . . . we knew this before we wrote the above equation, since the sum of 4 numbers is 4 times their average.

x = -18 . . . . . . . . the middle number of the sequence

So, the numbers are:

-18-3 = -21
-18-1 = -19
-18+1 = -17
-18+3 = -15

_____

A more conventional approach is to define the variable as the integer at one end or the other of the sequence. If we make it be the lowest number, then the equation is ...

(x) +(x +2) +(x +4) +(x +6) = -72

and that simplifies to ...

4x +12 = -72 . . . . . collect terms

4x = -84 . . . . . . . . subtract 12

x = -21 . . . . . . . . . . divide by 4

Now, the other three numbers are found by adding 2, 4, and 6 to this one.

3 0

3 years ago