To mix his special energy drink, Jerome uses 8 cups of water and 3 cups of drink mix.

bixtya [17]

Terms : “a” and “b”
Coefficients: 12, -10, and 6
Hope this helps :)

7 0

2 years ago

My brother wants to estimate the proportion of Canadians who own their house.What sample size should be obtained if he wants the

AVprozaik [17]

Answer:

a) $n=\frac{0.675(1-0.675)}{(\frac{0.02}{1.64})^2}=1475.07$

And rounded up we have that n=1476

b) $n=\frac{0.5(1-0.5)}{(\frac{0.02}{1.64})^2}=1681$

And rounded up we have that n=1681

Step-by-step explanation:

Previous 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 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 population proportion have the following distribution

$p \sim N(p,\sqrt{\frac{\hat p(1-\hat p)}{n}})$

The margin of error for the proportion interval is given by this formula:

$ME=z_{\alpha/2}\sqrt{\frac{\hat p (1-\hat p)}{n}}$ (a)

If solve n from equation (a) we got:

$n=\frac{\hat p (1-\hat p)}{(\frac{ME}{z})^2}$ (b)

Part a

In order to find the critical value we need to take in count that we are finding the interval for a proportion, so on this case we need to use the z distribution. Since our interval is at 90% of confidence, our significance level would be given by $\alpha=1-0.9=0.1$ and $\alpha/2 =0.05$ . And the critical value would be given by:

$z_{\alpha/2}=\pm 1.64$

The margin of error for the proportion interval is given by this formula:

$ME=z_{\alpha/2}\sqrt{\frac{\hat p (1-\hat p)}{n}}$ (a)

And on this case we have that $ME =\pm 0.02$ and we are interested in order to find the value of n, if we solve n from equation (a) we got:

$n=\frac{\hat p (1-\hat p)}{(\frac{ME}{z})^2}$ (b)

And replacing into equation (b) the values from part a we got:

$n=\frac{0.675(1-0.675)}{(\frac{0.02}{1.64})^2}=1475.07$

And rounded up we have that n=1476

Part b

For this case since we don't have a prior estimate we can use $\hat p =0.5$

$n=\frac{0.5(1-0.5)}{(\frac{0.02}{1.64})^2}=1681$

And rounded up we have that n=1681

8 0

3 years ago

Buck rented a truck for $39.95 plus $0.32 per mile. Before returning the truck, he Filled the tank with gasoline, which cost $9.

wel

Answer:

Step-by-step explanation:

Let x represent the distance that the truck was driven.

Buck rented a truck for $39.95 plus $0.32 per mile. This means that the total cost of driving x miles with the truck would be

39.95 + 0.32x

Before returning the truck, he Filled the tank with gasoline, which cost $9.85. This means that the total amount that he spent is

39.95 + 0.32x + 9.85

If the total cost was $70.23, it means that

39.95 + 0.32x + 9.85 = 70.23

49.8 + 0.32x = 70.23

0.32x = 70.23 - 49.8 = 20.43

x = 20.43/0.32 = 63.8

Approximately 64 miles

5 0

3 years ago

If person A pushes a box with 30 N of force to the right and person B pushes a box with 30 N of force to the left, what is the n

STatiana [176]

Answer:

balanced

Step-by-step explanation:

3 0

3 years ago

The measures of complementary angles have a sum of 90 degrees.Angle A and angle B are complimentary, and their measures have a d

777dan777 [17]

Answer:

The measure of the angles are 55° and 35°

Step-by-step explanation:

Sum of two angles that are complement of each other are 90.

The angles are A and B, so we can write:

A + B = 90

Also,

The difference is 20. Let A be the greater of them, so we can write equation 2 as:

A - B = 20

Now, we add up both equations, eliminate B and solve for A first:

A + B = 90

A - B = 20

---------------

2A = 90 + 20

2A = 110

A = 110/2

A = 55

And now the measure of B:

A + B = 90

55 + B = 90

B = 90 - 55

B = 35

5 0

4 years ago