Statistics Chapter 7 Homework
Ch. 7 Pr. 1
For a population containing N=902 individuals, what code number would you assign for; a. The first person on the list= 001 b. The fortieth person on the list= 040 c. The last person on the list= 902
Ch. 7 Pr. 13
What additional information would you want to know about the survey before you accepted the results of the study?
-Why was the study conducted? –What was the margin of error? –What was the sample size? -What sampling design was used? –What was the response rate? –What was the frame that was used? -Who paid for the survey? –From the sample that was selected, what was the population?
Ch. 7 Pr. 17
For each of the following three populations, indicate what the sampling distribution for samples of 25 would consist of: a. Travel expense vouchers for a university in an academic year.
-The sampling distribution of a sample means is the distribution of means from all possible samples of 25 vouchers that could possibly happen.
Ch. 7 Pr.24
A random sample of 50 households as selected for a telephone survey. The key question asked was, “Do you or any member of your household own a cellular telephone with a built in camera?” Of the 50 respondents, 15 said yes and 35 said no. a. Determine the sample proportion, p, of households with cellular telephones with built-in cameras.
P=x/n
P=15/50=0.30
-30% of the households surveyed had cell phones with cameras. b. If the population proportion is 0.40 determine the standard error of the proportion.
-We can use the standard normal curve for binomial data in cases where we have a big sample.
Ch. 7 Pr. 33
Why is the sample mean an unbiased estimator of the population mean?
-The sample mean is an unbiased estimator of the population means due to the average of all of the possible sample means of a size is equal to the population mean.
Ch. 7 Pr. 34
Why does the standard error of the mean decrease as the sample size, n, increases?
-Variation of the sample means becomes
For a population containing N=902 individuals, what code number would you assign for; a. The first person on the list= 001 b. The fortieth person on the list= 040 c. The last person on the list= 902
Ch. 7 Pr. 13
What additional information would you want to know about the survey before you accepted the results of the study?
-Why was the study conducted? –What was the margin of error? –What was the sample size? -What sampling design was used? –What was the response rate? –What was the frame that was used? -Who paid for the survey? –From the sample that was selected, what was the population?
Ch. 7 Pr. 17
For each of the following three populations, indicate what the sampling distribution for samples of 25 would consist of: a. Travel expense vouchers for a university in an academic year.
-The sampling distribution of a sample means is the distribution of means from all possible samples of 25 vouchers that could possibly happen.
Ch. 7 Pr.24
A random sample of 50 households as selected for a telephone survey. The key question asked was, “Do you or any member of your household own a cellular telephone with a built in camera?” Of the 50 respondents, 15 said yes and 35 said no. a. Determine the sample proportion, p, of households with cellular telephones with built-in cameras.
P=x/n
P=15/50=0.30
-30% of the households surveyed had cell phones with cameras. b. If the population proportion is 0.40 determine the standard error of the proportion.
-We can use the standard normal curve for binomial data in cases where we have a big sample.
Ch. 7 Pr. 33
Why is the sample mean an unbiased estimator of the population mean?
-The sample mean is an unbiased estimator of the population means due to the average of all of the possible sample means of a size is equal to the population mean.
Ch. 7 Pr. 34
Why does the standard error of the mean decrease as the sample size, n, increases?
-Variation of the sample means becomes