# probability and statistics data collection

__Complete questions #1 – 2. Show Work__

1. A survey was done to determine the texting habits of MBHS students. An SRS of 270 students were asked several questions related to texting and cell phone usage. Of particular interest to the researchers was the proportion of students who text while in class. Of those surveyed, 178 said that they text during class at least ten times per week. Identify each of the following as specifically as possible.

a. Population of Interest

b. Parameter of Interest

c. Sample

d. Statistic

e. Margin of Error

f. 95% Confidence Interval

g. Confidence Statement

h. Do you personally feel that this is too high or too low of an estimate of the proportion of teens at your high school who text during class?

2. To predict the outcome of an upcoming Mayoral election, a random sample of 814 voters was selected. These people are asked several questions regarding the election. One question asked whether they were â€œâ€¦leaning Republican, Democratic, Independent, or other/undecided?â€ Based on this question, 38.2% of respondents said that they were â€œâ€¦leaning Democraticâ€¦â€. Identify each of the following as specifically as possible.

a. Population of Interest

b. Parameter of Interest

c. Sample

d. Statistic

e. Margin of Error

f. 95% Confidence Interval

g. Confidence Statement

__Complete questions #1 â€“ 9. Show work. __

(Questions #1-6: Mr. Henderson is trying to learn about how his past students feel about him as a teacher. He mailed a personalized letter and â€œTeacher Satisfaction Surveyâ€ to all 3100 students that he has taught in his teaching career. Of the 1603 people who returned the survey, 57.8% thought that Mr. Henderson was an effective teacher.)

1. What type of survey/statistical study did Mr. Henderson attempt to do by contacting every student that he has ever taught?

2. What type of survey/statistical study actually happened (not everyone returned the survey)?

3. Who is the population in this scenario?

4. What is the parameter for Mr. Hendersonâ€™s study?

5. What is the statistic?

6. Find the Margin of Error for this scenario, write the Confidence Interval, and then make a 95% Confidence Statement (be sure to show work that supports your answers).

7. What is the Margin of Error for a 95% Confidence Interval if the sample size is 400 individuals?

8. Give an example of something that would be considered a numerical variable and something that would be considered a categorical variable (be sure to label which is which).

(Question 9: You are part of a group of medical researchers planning an experiment to test whether aspirin helps prevent repeated heart attacks. The subjects are 700 male heart attack patients under 60 years old. You hope that taking 325 mg. of aspirin each day will prevent future heart attacks. The subjects will be observed for a five-year period.)

9. You have the names of all 700 subjects and have numbered them 001-700. Use the random digit table to select the first five participants

80940 70029 17868 40743 68990 90656 87964 18883