Recent questions in Samples

College StatisticsAnswered question

tac62txC 2022-11-25

1. A sample is chosen randomly from a population model that was strongly skewed to the right with m =145 and s =100 .

a. If we draw a random sample of n = 1000 from this population, what will be the shape of the histogram based this sample? What would be your best guess of mean and standard deviation of this sample?

b. If we draw 10,000 samples of size n = 1000 from this population, what will be the shape of the histogram of the sample means. What would be your best guess of sample mean and sample standard deviation of the distribution represented by this histogram?

a. If we draw a random sample of n = 1000 from this population, what will be the shape of the histogram based this sample? What would be your best guess of mean and standard deviation of this sample?

b. If we draw 10,000 samples of size n = 1000 from this population, what will be the shape of the histogram of the sample means. What would be your best guess of sample mean and sample standard deviation of the distribution represented by this histogram?

College StatisticsAnswered question

charmbraqdy 2022-11-19

Why is a sample statistic a random variable?

College StatisticsAnswered question

Nola Aguilar 2022-11-15

For a continuous random variable x, the population mean and standard deviation are 120 and 15 respectively. How do you find the mean and standard deviation of the sampling distribution of the sample mean for a sample of 25 elements?

College StatisticsAnswered question

limfne2c 2022-10-29

What is the mean of the sampling distribution of the sample mean x if a sample of 64 students is selected at random from the entire freshman class?

College StatisticsAnswered question

Rubi Garner 2022-10-24

Suppose that the sample mean for a random sample of 110 cars is 28.3 miles and assume the standard deviation is 3.2 miles. Is 26.9 against the alternative hypothesis that it is not 26.9? What is the test statistic?

College StatisticsAnswered question

Aldo Ashley 2022-10-22

If the sample mean = 16, population mean = 8, sample standard deviation = 4, and sample size = 150, what is the one sided t-score of the sample?

College StatisticsAnswered question

Eliza Gregory 2022-10-22

A sample of 50 values has a mean of 8.33 while the population standard deviation is 0.67. According to the Central Limit Theorem, the distribution of sample means is what?

College StatisticsAnswered question

Oscar Burton 2022-10-18

As sample size increases, what happens to the standard error of M?

College StatisticsAnswered question

Rubi Garner 2022-10-18

Do all pure samples of a given compound have the same percent composition?

College StatisticsAnswered question

Keyla Koch 2022-10-17

How do you calculate the sample range, sample mean, sample median, sample variance, and sample standard deviation of 18, 19, 34, 38, 24, 18, 22, 51, 44, 14, 29?

College StatisticsAnswered question

Winston Todd 2022-10-16

You are the assistant manager at Extra Credit Union. Your boss, Robin Banks, has sent you the following email:

"Assistant Manager, as you know, we go the extra mile in our service to our clients. Part of that is knowing our clients well. Thus, we are wanting to solicit phone-call feedback from some of our clients. I know we don't have time to talk to all 10,000 clients, so I am wanting a smaller representative sample. Perhaps a random sample of 25 or 50 would be good. Across all 10,000 clients, the average account balance is $12,000 and the standard deviation is $5000. I want the sample we take to closely match our clients as a whole. Specifically, I want the probability to be at least 80% that the average of our sample is within $1000 of the average for all clients. Would a random sample of 25 be fine or do we need to take a random sample of 50? Use the magical statistics skills you learned back in college and get back to me ASAP! Thanks, Robin Banks"

In your response indicate whether 25 is sufficient or whether a sample of 50 would be necessary. (You will want to calculate the probability of the sample mean being between $11,000 and $13,000 for both a sample size of 25 and 50.)

"Assistant Manager, as you know, we go the extra mile in our service to our clients. Part of that is knowing our clients well. Thus, we are wanting to solicit phone-call feedback from some of our clients. I know we don't have time to talk to all 10,000 clients, so I am wanting a smaller representative sample. Perhaps a random sample of 25 or 50 would be good. Across all 10,000 clients, the average account balance is $12,000 and the standard deviation is $5000. I want the sample we take to closely match our clients as a whole. Specifically, I want the probability to be at least 80% that the average of our sample is within $1000 of the average for all clients. Would a random sample of 25 be fine or do we need to take a random sample of 50? Use the magical statistics skills you learned back in college and get back to me ASAP! Thanks, Robin Banks"

In your response indicate whether 25 is sufficient or whether a sample of 50 would be necessary. (You will want to calculate the probability of the sample mean being between $11,000 and $13,000 for both a sample size of 25 and 50.)

College StatisticsAnswered question

Nathanial Levine 2022-10-03

How many different phone numbers are possible in the area code 928? Note: Phone numbers cannot start with 0 or 1.

College StatisticsAnswered question

Aidyn Crosby 2022-10-02

At a football game, a researcher randomly asks 100 people to name their favorite sport. Is this a biased sample?

College StatisticsAnswered question

amhailim 2022-09-27

When should blood samples for trough drug levels be collected?

College StatisticsAnswered question

Kaila Branch 2022-09-27

What is the mode of the following numbers? $12,11,14,10,8,13,11,9$

$a11\phantom{\rule{0ex}{0ex}}b.10\phantom{\rule{0ex}{0ex}}c.14\phantom{\rule{0ex}{0ex}}d.8$

$a11\phantom{\rule{0ex}{0ex}}b.10\phantom{\rule{0ex}{0ex}}c.14\phantom{\rule{0ex}{0ex}}d.8$

College StatisticsAnswered question

fion74185296322 2022-09-26

In what way are voluntary response samples often biased?

College StatisticsAnswered question

Logan Knox 2022-09-17

A chemist weighed three separate test samples at 0.17 gram, 0.204 gram, and 2.3 grams. What is the total weight of the three samples?

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Statistics samples are a way for researchers to learn about a population by studying a smaller group. They allow researchers to make conclusions about a larger group based on data gathered from a sample that represents the population. Sampling methods aim to create a sample that accurately reflects the population and minimizes bias. Samples are also used to test hypotheses about the population and gather insights that would be difficult to obtain otherwise.