Introduction to the Practice of Statistics
Section 1.1 - Introduction to the Practice of Statistics
1. Explain the difference between a population and a sample.
A population is the entire group to be studied and a sample is a portion of the population.
2. Explain the difference between a parameter and a statistic.
A statistic is a numerical summary of a sample and a parameter is a numerical summary of a population.
3. What is Descriptive Statistics and how is it used?
Descriptive statistics describes the results of a sample without making conclusions of the population.
4. What is Inferential Statistics and how is it used?
Inferential statistics uses the result of a sample to apply to a population.
5. Determine whether the following variables are qualitative or quantitative.
Variable Type of Variable
Number of siblings Quantitative
The number of a football player's jersey Qualitative
The assessed value of a house Quantitative
The day of the week Qualitative
6. Determine whether the following quantitative variables are continuous or discrete.
Variable Type of Variable
Volume of water lost each day through a leaky faucet Continuous
Number of trees on a randomly selected acre of land Discrete
Internet connection speed in kilobytes per second Continuous
Air pressure in pounds per square inch in an automobile tire Continuous
7. Determine whether the following underlined variable is a parameter or statistic.
Variable Type of Variable
Calculus Exam: In the Spring 2008 semester a college had a total of 11 Calculus 101 classes. The average score for one class of 25 students taking the Calculus 101 midterm exam was 72%. Statistic
Calculus Exam: The average score for a class of 28 students taking a calculus midterm exam was 84%. Parameter
Moonwalkers: Only 12 men have walked on the moon. The average age of these 12 men is at the time of their moonwalks was 39 years, 11 months, 15 days. Parameter
Alcohol Use: In a national survey on substance abuse, 66.4% of
1. Explain the difference between a population and a sample.
A population is the entire group to be studied and a sample is a portion of the population.
2. Explain the difference between a parameter and a statistic.
A statistic is a numerical summary of a sample and a parameter is a numerical summary of a population.
3. What is Descriptive Statistics and how is it used?
Descriptive statistics describes the results of a sample without making conclusions of the population.
4. What is Inferential Statistics and how is it used?
Inferential statistics uses the result of a sample to apply to a population.
5. Determine whether the following variables are qualitative or quantitative.
Variable Type of Variable
Number of siblings Quantitative
The number of a football player's jersey Qualitative
The assessed value of a house Quantitative
The day of the week Qualitative
6. Determine whether the following quantitative variables are continuous or discrete.
Variable Type of Variable
Volume of water lost each day through a leaky faucet Continuous
Number of trees on a randomly selected acre of land Discrete
Internet connection speed in kilobytes per second Continuous
Air pressure in pounds per square inch in an automobile tire Continuous
7. Determine whether the following underlined variable is a parameter or statistic.
Variable Type of Variable
Calculus Exam: In the Spring 2008 semester a college had a total of 11 Calculus 101 classes. The average score for one class of 25 students taking the Calculus 101 midterm exam was 72%. Statistic
Calculus Exam: The average score for a class of 28 students taking a calculus midterm exam was 84%. Parameter
Moonwalkers: Only 12 men have walked on the moon. The average age of these 12 men is at the time of their moonwalks was 39 years, 11 months, 15 days. Parameter
Alcohol Use: In a national survey on substance abuse, 66.4% of