Question

STAT 200 Week 1 Homework Problems

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

1.1.8 The World Health Organization wishes to estimate the mean density of people per square kilometer, they collect data on 56 countries. 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.

1.4.8 Suppose a telephone poll is conducted by contacting U.S. citizens via landlines about their view of same sex marriage. Suppose over 50% of those called do not support same sex marriage. Does that mean that you can say over 50% of all people in the U.S. do not support same sex marriage? 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 this data. State any findings you see from the graphs.

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%

Answer 1

Individual (basic unit of study from which information is collected) - a Connecticut household

Variable (the value or item that is measured) - Type of fuel used as heating source

Population (the whole set of individuals regarding which the conclusion is to be drawn) - All Connecticut households

Sample (the sub-group of population that is selected for study) - The 1000 Connecticut households

Parameter (the numerical value that represents a particular nature or character of the population) - Percentage of households in Connecticut which use fuel oil as a heating source.

Statistic (the numerical value that represents a particular character of the sample) - Percentage of households among the 1000 selected which use fuel oil as a heating source

The matched options are -

1. Households in Connecticut - Individual to be include in the study

2. percentage of households in Connecticut who use fuel oil as heating source - Variable to be measured in the study

3. set of all responses of Connecticut households as to heating source - Population data

4. set of 1000 responses of Connecticut households as to heating source - Sample data

5. percentage of those who use fuel oil as heating source calculated from the population of Connecticut households - Parameter (percentage that summarize data for an entire population)

6. percentage of those who use fuel oil as heating source calculated from the sample of 1000 Connecticut households - Statistic (percentage that summarize sample data)

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

Individual - Households in Connecticut.

Variable - Percentage of households in Connecticut which use fuel oil as a heating source.

Population - All responses from the samples.

Sample - 1000 Connecticut households.

Parameter - Percentage of household which use fuel oil as heating source.

Statistic - Percentage of households which use fuel oil as heating source and other methods of heating sources taken from the samples.
1.1.8 The World Health Organization wishes to estimate the mean density of people per square kilometer, they collect data on 56 countries. State the individual, variable, population, sample, parameter, and statistic

Individual - One country out of the 56 samples.

Variable - The mean density of people per square kilometer from all 56 samples.

Population - All the countries in the world.

Sample - 56 countries.

Parameter - The mean density of people per square kilometer from all the countries in the world.

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 this data. State any

findings you see from the graphs.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%