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Probability and Statistics
HW 1 – Basic Terms
1.
Name______________________________
Determine which of the following statements is descriptive and which is inferential. a.
82% of all U.S. students prefer to eat snacks at home. b.
82% of the 1746 U.S. students polled prefer to eat snacks. c.
The average age of the surveyed travelers is 38 years. d.
54% of all American long-distance travelers are men.
2. The following three statistics were reported on a radio broadcast: (1) the U.S. divorce rate is 55%; and when married adults were asked whether they would remarry their spouse, (2) 75% of the women said yes and (3) 65% of the men said yes. a.
What is the “stay married” percentage? b.
There seems to be a contradiction in this information. How is it possible for all three of these statements to be correct? Explain.
3. A working knowledge of statistics is very helpful when you want to understand the statistics reported in the news. The news media and our government often make statements like “Crime rate jumps 50% in your city.” a.
Does an increase in the crime rate from 4% to 6% represent an increase of
50%? Explain. b. Why would anybody report an increase from 4% to 6% as a 50% rate jump?
Is football jersey number a quantitative or qualitative variable?
The severity of side-effects suffered by patients is measured on the scale: none, mild, moderate, severe, very severe. a.
Name the variable of interest. b.
Identify the type of variable.
5. Students are being surveyed about the weight of books and supplies they are carrying as they attend class. a.
Identify the variable of interest. b.
Identify the type of variable. c.
List a few values that might occur in a sample.

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A drug manufacturer is interested in the proportion of persons who have hypertension whose condition can be controlled by a new drug the company has developed. A study involving 5000 individuals with hypertension is conducted, and it is found that 80% of the individuals are able to control their hypertension with the drug. Assuming that the 5000 individuals are representative of the group who have hypertension, answer the following questions: a.
What is the population? b.
What is the sample? c.
Identify the parameter of interest. d.
Identify the statistic and give its value. e.
Do we know the value of the parameter?
Identify each of the following as an example of either qualitative or quantitative variables. a.
the breaking strength of a given type of string b.
the hair color of children auditioning for the musical Annie c.
the number of stop signs in towns of less than 500 people d.
whether or not a faucet is defective e.
the number of questions answered correctly on a standardized test f.
the length of time required to answer a phone call at an office
Identify each of the following as an example of nominal, ordinal, discrete, or continuous variables: a.
a poll of registered voters about which candidate they support b.
the length of time required for a wound to heal when a new medicine is use c.
the number of telephone calls arriving at a switchboard in a 10-min period d.
the distance first-year college women can kick a football e.
the number of pages per job coming off a computer printer f.
the kind of tree used as a Christmas tree
Explain the difference between a statistic and a parameter and why we’d choose to report a statistic over a parameter.