the jacksons went camping in a state park.One of the tents they took is shown . What is the volume of the tent.

A marketing manager samples 150 people and finds that 87 of them have made a purchase on the internet within the past month. a.

expeople1 [14]

Answer:

a) $\hat p = \frac{87}{150}= 0.58$

b) We assume for this case a confidence level of 95%

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

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

$n=\frac{0.58(1-0.58)}{(\frac{0.03}{1.96})^2}=1039.793$

And rounded up we have that n=1040

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

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

Solution to the problem

Part a

For this case the estimated proportion of people who have made a purchase on the internet within the past month is given by:

$\hat p = \frac{87}{150}= 0.58$

Part b

We assume for this case a confidence level of 95%

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 95% of confidence, our significance level would be given by $\alpha=1-0.95=0.05$ and $\alpha/2 =0.025$ . And the critical value would be given by:

$t_{\alpha/2}=-1.96, t_{1-\alpha/2}=1.96$

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 $ME =\pm 0.03$ 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:

$n=\frac{0.58(1-0.58)}{(\frac{0.03}{1.96})^2}=1039.793$

And rounded up we have that n=1040

4 0

2 years ago

You place a cup of 200 degrees F coffee on a table in a room that is 67 degrees F, and 10 minutes later, it is 195 degrees F. Ap

Marat540 [252]

195=67+(200-67)e^(-10k)

195=67+133e^(-10k)

128=133e^(-10k)

128/133=e^(-10k)

ln(128/133)=-10k

k=-ln(128/133)/10

T(t)=67+133e^(tln(128/133)/10), if T(t)=180

180=67+133e^(tln(128/133)/10)

113=133e^(tln(128/133)/10)

113/133=e^(tln(128/133)/10)

ln(113/133)=tln(128/133)/10

10ln(113/133)=tln(128/133)

t=10ln(113/133)/ln(128/133)

t≈42.5 minutes...

t≈40 minutes (to nearest 5 minutes? :P)

4 0

2 years ago

Read 2 more answers

Pat had 9 flowerpots, and she wants to plant a different type of flower in each one. There are 11 types of flowers available at

wariber [46]

<span>In this problem, we will use the combination since the order does not matter but the flower can only be selected once. From the given, we have a total of 11 flower and 9 flowerpots, to get the number of possible combinations, we can write is at 11C9 or 11! / {9! (11-9)!}. The total number of possible combinations is 55</span>

7 0

2 years ago

Read 2 more answers

The probability that Evan purchases a comic book from the bookstore (event A) is 0.67, and the probability that Glen purchases a

Sveta_85 [38]

The question is asking to choose among the following choices that states the statement that is true about the said information and base on the given data, I would say the answer among them is <span>Events A and B are dependent because P(A and B) do not equal P(A) x P(B). I hope you are satisfied with my answer and feel free to ask for more</span>

7 0

2 years ago

Read 2 more answers

Suppose you want to assess student attitudes about the new campus center by surveying 100 students at your school. In this examp

sleet_krkn [62]

Answer:

Suppose you want to assess student attitudes about the new campus center by surveying 100 students at your school. In this example, the group of 100 students represents the Sample, and all of the students at your school represent the Population.

Step-by-step explanation:

Previous concepts

The term sample represent a set of observations or individuals selected from a population. And we can have a random sample (when all the individuals have the same probability of being selected) or a non random sample (when not all the individuals have probability of inclusion into the sample)

The term population represent the total of observations or individuals with a common characteristic.

If N represent the sample of the population and n the sample size we have always this inequality:

$n \leq N$

Solution to the problem

Suppose you want to assess student attitudes about the new campus center by surveying 100 students at your school. In this example, the group of 100 students represents the Sample, and all of the students at your school represent the Population.

3 0

2 years ago