Statistic

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Question 1- 10

Determine which of the four levels of measurement is most appropriate for the statement below.

Ages of survey respondents.

 A. Ratio                B. Interval          C. Ordinal             D. Nominal

Question 2 of 10

A botany student counted 11 blades of grass in one square centimeter of lawn and measured the lawn as a rectangle 61 m by 31 m. She reported that there were 208,010,000 blades of grass in the lawn. The precision of her conclusion:

  A. correctly represents her measurements.     

  B. is less than her measurements warrant.        

  C. could be greater if she used a more precise calculator.           

  D. is excessive given her measurements.

Question 3 of 10

Data has been collected from a representative sample of a well-defined population to answer the question: “How much money does the average senior male at Normal Community High School have in his pockets at the end of the school day on Friday?” The next step in the study is to:

  A. determine the margin of error.         

  B. summarize the data with a sample statistic.

  C. use the collected data to make inferences about the population.      

  D. summarize the data with a sample parameter.

Question 4 of 10

The results of a poll are stated as follows: “Based on a survey of 156 randomly selected students, 90% of the student body of 2870 students agree that no student should have to take final exams in two consecutive exam periods”. If 2578 students actually agree, then what is the absolute error in the reported result?

  A. 5 students     B. 287 students                 C. 0.17%               D. 292 students              

Question 5 of 10

Two statements are given below. Select the statement for which a ratio of the measurements is meaningful. State “Neither” or “Both” if appropriate.

1 – Kasheta ran the race in 22.3 sec, and Louisa ran the same race in 26.4 sec.

2 – Juan gets out of school at 2:45 PM, and Aito gets out of school at 3:15 PM.

 A. Kasheta ran the race in 22.3 sec, and Louisa ran the same race in 26.4 sec.     

  B. Neither        

  C. Both              

  D. Juan gets out of school at 2:45 PM, and Aito gets out of school at 3:15 PM.   

Question 6 of 10

Which is the best fertilizer for Mr. Jimenez’ backyard grass? Select the type of study most appropriate to the question.

 A. Experimental   B. Experimental blinded   C. Case-controlled observational        D. Observational            

Question 7 of 10

In a survey of 80 high school football players who committed to play in the Division III CCIW conference, 64 said that they would work out in their high school weight rooms in the summer before college. The margin of error for the survey was 6%. A census of all CCIW football players (not just freshmen) showed that 59% worked out at their high schools. One can conclude that:

  A. the subjects were less than forthcoming in their responses to the survey.   

  B. the sample was not representative of the population.           

  C. there must have been an error in the determination of the margin of error.                

  D. the census results are consistent with the confidence interval of the study.

Question 8 of 10

The size of an e-mail file is stated as 210 kB, but the file size is actually 220.5 kB. What is the absolute error?

  A. 5%     B. 10%                   C. 10.5 kB           D. -10.5 kB

Question 9 of 10

One month before a recall election, a poll of 500 Wisconsin voters showed that 46% planned to vote for the Democratic challenger Tom Barrett and 45% planned to vote for Republican Governor Scott Walker. Undecided voters constituted another 9%. The margin of error was 5 percentage points. What conclusion can you draw from this poll?

  A. Barrett will win the election.                  B. Walker can’t get over 50% of the votes.        

  C. The race is too close to call.    D. No one will win.      

Question 10 of 10

0.0/ 5.0 Points

A U.S. government report stated that, “With bank interest rates around 1.0%, 8% of wage earners believe it worthwhile to keep money in a savings account. However, at 3.0% interest, 36% of wage earners believe it worthwhile to keep money in a savings account. The margin of error for both studies is 4 percentage points.”. A proper conclusion from the studies is that:

  A. increasing the interest rate from 1% to 3% will increase the number of persons saving money in a savings account.              

  B. increasing the interest rate may well have no effect on the number of persons saving money in a savings account.              

  C. increasing the interest rate will increase the number of persons saving money in a savings account.

  D. the interest rate difference between 1% and 3% may well have no effect on the number of persons saving money in a savings account.