STAT 200 CASE STUDY

STAT 200 Week 1 Homework

1.1.4

To estimate the percentage of households in Connecticut which use fuel oil as a heating source, a researcher collects information from 1000 Connecticut households about what fuel is their heating source. State the individual, variable, population, sample, parameter, and statistic

1.2.4

You wish to determine the GPA of students at your school. Describe what process you would go through to collect a sample if you use a stratified sample.

1.3.4

To evaluate whether a new fertilizer improves plant growth more than the old fertilizer, the fertilizer developer gives some plants the new fertilizer and others the old fertilizer. Is this an observation or an experiment? Why?

1.3.10

A mathematics instructor wants to see if a computer homework system improves the scores of the students in the class. The instructor teaches two different sections of the same course. One section utilizes the computer homework system and the other section completes homework with paper and pencil. Are the two samples matched pairs or not? Why or why not?

1.3.16

To determine if a new medication reduces headache pain, some patients are given the new medication and others are given a placebo. Neither the researchers nor the patients know who is taking the real medication and who is taking the placebo. Is this a blind experiment, double blind experiment, or neither? Why?

1.4.2

Suppose a car dealership offers a low interest rate and a longer payoff period to customers or a high interest rate and a shorter payoff period to customers, and most customers choose the low interest rate and longer payoff period, does that mean that most customers want a lower interest rate? Explain.

1.4.14

An employee survey says, “Employees at this institution are very satisfied with working here. Please rate your satisfaction with the institution.” Discuss how this question could create bias.

2.1.4

In Connecticut households use gas, fuel oil, or electricity as a heating source. Table #2.1.7 shows the percentage of households that use one of these as their principle heating sources (“Electricity usage,” 2013), (“Fuel oil usage,” 2013), (“Gas usage,” 2013).

Create a bar chart and pie chart of these data. (15 points)

State any findings you see from the graphs. (10 points)

Table #2.1.7: Data of Household Heating Sources

Heating   Source     Percentage

Electricity                  15.3%

Fuel Oil                     46.3%

Gas                           35.6%

Other                           2.8%