Evaluate the expression and enter your answer below. 5•(4+5)

What is the value of 9 - [42 - (3 + 2)].

Vlada [557]

9 - [42 - (3 + 2)]

Parentheses first:

9-[42-5]

Brackets next:

9- 37

Now subtract to get -28

8 0

3 years ago

Prism M and pyramid N have the same base area and the same height. Cylinder P and prism Q have the same height and the same base

m_a_m_a [10]

Answer:

Answer Cone Z and Cylinder Y.

Step-by-step explanation:

The relationship between the volume of the cone and the volume of the cylinder with the same height and same base is the volume of the cone is 1/3 of the volume of the cylinder.

The formula for the volume of the cone is :

V = 1/3π $r^{2}$ h

The formula for the volume of the cylinder is :

V = π $r^{2}$ h

Let be the height of the cylinder Y. Therefore the height of the cone Z is 3h, when we put it into the formula we get :

V = 1/3π $r^{2}$ (3h) = π $r^{2}$ h

Therefore Cone Z and Cylinder Y have same volume.

8 0

4 years ago

Read 2 more answers

Next, rearrange the expression in part B using the Commutative Property so the terms with the same place value are next to each

Hunter-Best [27]

Answer:

70 + 2 + 0.3 + (-30) + (-9) + (-0.1) = 70 + (-30) + 2 + (-9) + 0.3 + (-0.1)

Step-by-step explanation:

i dont have an explanation but that is the answer i can confirm because i did it and got it wrong but then it showed the right answer hope it helps you

5 0

3 years ago

Read 2 more answers

6. Protein bars come in a 4-pack box or 12-pack

cricket20 [7]

Answer:

The 12 pack has a better value.

Step-by-step explanation:

1. create a ratio table.

you want to know how much the 4 pack would cost if it was a 12 pack.

you can see the ratio table in the picture above.

As you can see, when the 4 pack equals $7.68, making it a 12 pack will equal $23.04.

Then, compare 23.04 to 22.32.

In conclusion, the 12 pack has a better value.

5 0

4 years ago

Estimate the minimum and maximum ages for typical textbooks currently used in college courses, then use the range rule of thumb

Maksim231197 [3]

Answer:

$n=(\frac{1.64(4)}{0.25})^2 =688.537 \approx 689$

So the answer for this case would be n=689 rounded up to the nearest integer

Step-by-step explanation:

Assuming this complete question: "Suppose that the minimum and maximum ages for typical textbooks currently used in college courses are 0 and 8 years. Use the range rule of thumb to estimate the standard deviation.

Estimate the minimum and maximum ages for typical textbooks currently used in college courses, then use the range rule of thumb to estimate the standard deviation. Next, find the size of the sample required to estimate the mean age (in years) of textbooks currently used in college courses. Use a 90% confidence level and assume that the sample mean will be in error by no more than 0.25 year."

Solution for the problem

First we need ti find the estimation for the standard deviation using the Rule of thumb, with the following formula:

$s \approx \frac{R}{4}$

Where R is the range defined as :

$R = Max - Min = 8-0 = 8$

So then the deviation would be approximately:

$s \approx 4$

Important concepts

A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population means lies between an upper and lower interval".

The margin of error (ME) is the range of values below and above the sample statistic in a confidence interval.

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".

The margin of error is given by this formula:

$ME=z_{\alpha/2}\frac{\sigma}{\sqrt{n}}$ (1)

And on this case we have that $ME =\pm 0.25$ and we are interested in order to find the value of n, if we solve n from equation (1) we got:

$n=(\frac{z_{\alpha/2} \sigma}{ME})^2$ (2)

We can assume that the estimator for the population deviation from the rule of thumb is $\hat \sigma = s= 4$

The critical value for 90% of confidence interval now can be founded using the normal distribution. And in excel we can use this formla to find it:"=-NORM.INV(0.05;0;1)", and we got $z_{\alpha/2}=1.64$ , replacing into formula (2) we got:

$n=(\frac{1.64(4)}{0.25})^2 =688.537 \approx 689$

So the answer for this case would be n=689 rounded up to the nearest integer

6 0

3 years ago

Evaluate the expression and enter your answer below. 5•(4+5) - 7^2