Problem

Marijuana Survey Exercise referred to a Pew poll of 1500 adults, and 52% of the respondents said that the use of marijuana should not be made legal.

a. Among the 1500 adults who responded, what is the number of respondents who said that the use of marijuana should not be made legal?

b. In the same poll of 1500 adults, 345 of the respondents said that the use of marijuana for medical purposes should not be legal. What is the percentage of respondents who said that the use of marijuana for medical purposes should not be legal?

c. In this survey of 1500 adults, 727 are men and 773 are women. Find the percentage of respondents who are men, and then find the percentage of respondents who are women.

d. Does the difference between the two percentages from part (c) appear to have statistical significance?

e. Does the difference between the two percentages from part (c) appear to have practical significance?

Exercise

Marijuana Survey In a recent Pew poll of 1500 adults, 52% of the respondents said that the use of marijuana should not be made legal. In the same poll, 23% of the respondents said that the use of marijuana for medical purposes should not be legal.

a. The sample of 1500 adults was selected from the population of all adults in the United States. The method used to select the sample was equivalent to placing the names of all adults in a giant bowl, mixing the names, and then drawing 1500 names. What type of sampling is this? (random, systematic, convenience, stratified, cluster)

b. If the sampling method consisted of a random selection of 30 adults from each of the 50 states, what type of sampling would this be? (random, systematic, convenience, stratified, cluster)

c. What is the level of measurement of the responses of yes, no, don’t know, and refused to respond?

d. Is the given value of 52% a statistic or a parameter? Why?

e. What would be wrong with conducting the survey by mailing a questionnaire that respondents could complete and mail back?

Answer:

Step1 of 6:

Given exercise referred to a Pew poll of 1500 adults, and 52% of the respondents said that the use of marijuana should not be made legal.

Step 2 of 6:

a). Here we need to find, Among the 1500 adults who responded, what is the number of respondents who said that the use of marijuana should not be made legal?

First we have to convert the percentage to decimal form.

That is, 52% =

Then we have to Multiply the decimal (percentage) by the total number of respondents to get a number.

0.53

Therefore, 795 number of respondents who said that the use of marijuana should not be made legal.

Step 3 of 6:

b). Given, In the same poll of 1500 adults, 345 of the respondents said that the use of marijuana for medical purposes should not be legal.

Now we have to find the percentage of respondents who said that the use of marijuana for medical purposes should not be legal?

Write the numbers given into fraction form, with total as the denominator. And then Convert fraction to decimal form.

i.e,

Now, Multiply decimal by 100 to get a percentage.

i.e, 0.23 100 = 23%.

Therefore, 23% of respondents who said that the use of marijuana for medical purposes should not be legal.

Step 4 of 6:

c). Given, In this survey of 1500 adults, 727 are men and 773 are women.

Here we need to find the percentage of respondents who are men, and then find the percentage of respondents who are women.

Now,

Male =

Women = .

Multiply decimal by 100 to get a percentage.

i.e, male: 0.4847 100 = 48%

female:0.5153 100 = 52%.

Therefore, 48% men and 52% women.

Step 5 of 6:

d). We cannot say. Because we do not yet know how to find out whether something is statistically significant, passing any sort of judgement would be subjective.

Step 6 of 6:

e). We can not say. Because some may say that a 4% difference is significant while others may not think so as both percentages are relatively close to 50%. This is a subjective judgement.

Exercise:

Step 1 of 6: Given,In a recent Pew poll of 1500 adults, 52% of the respondents said that the use of marijuana should not be made legal. In the same poll, 23% of the respondents said that the use of marijuana for medical purposes should not be legal.

Step 2 of 6:

a). Random Sampling : a simple random sample is a sample chosen from a population.

This is a Random sampling, because everyone in the population have the equal chance of being selected.

Step 3 of 6:

b). Stratified sampling : The researcher divides the population into separate groups, called strata. Then, a probability sample (often a simple random sample ) is drawn from each group.

Here the sampling is stratified.

All the 50 states are the stratas and from each stratum 30 adults have been selected.