# A+ answers | Mathematics homework help

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Convert 5.65 to a percent.

A. 565%

B. 5.65%

C. 0.565%

D. 56.5%

Convert 5/16 to a percent.

A. 31.25%

B. 0.3125%

C. 3.125%

D. 0.03125%

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 agrees 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

A nutritionist wants to conduct a study to validate the efficacy of an herb as an aid in weight loss. She randomly assigns half of a group of overweight persons to a treatment group who are given the herb with instructions for its use and a planned diet for six weeks. The other half of the group is given parsley with the same instructions and same diet. A nurse at the nutrition center weighs each subject on Friday of each week. Select the potential source of confounding.

A. Placebo effect

B. Experimenter effect

C. Method of assignment to treatment and control groups

D. The study is essentially free of potential confounding.

A student wanted to know the favorite lunch at a large high school with a closed campus. What is the first step in conducting a statistical study to answer the question?

A. Select a random sample of students.

B. State the goal of the study precisely.

C. Select a random sample of students and teachers.

D. Select a random sample of teachers.

A college student who does laundry infrequently wants to determine the effect of bluing on what should be white clothes. Select the sample most representative of the population.

A. Reports of two friends, one of whom was given bluing

B. The reports of an internet chatroom on laundry techniques

C. Two loads of personal wash, one with, one without bluing

D. Two loads of wash, one personal, one of a friend, the bluing assigned by a coin flip

A poll of 700 persons attending the Taste of Chicago showed that 455 persons, 65% of the sample, believed that the food was overpriced. It is estimated that 1,250,000 persons attend the Taste. Statistics suggest that, although 65% plus or minus 5% of attendees believe that the food is overpriced, the Taste is a popular event. The raw data of the study is (are)

A. 65% of the sample.

B. 700 persons, 455 persons.

C. 1,250,000 persons, 700 persons, 455 persons.

D. (60%, 70%).

Humanities majors spend an average of $115 per course on books. Mathematics majors spend an average of $70 per course on books. What is the percent difference between the two amounts relative to the amount for mathematics majors (round to the nearest percent)?

A. 64%

B. 39%

C. 50%

D. 42%

A poll was taken of a random sample of 1189 college students. Of these students, 789 reported that they had a drinking binge (more than 10 drinks in an evening) in the past month. Select the most believable conclusion.

A. About 66.358% of college students indulged in binge drinking last month.

B. Of the 23,456,321 college students in the country, 15,565,212 indulged in binge drinking last month.

C. About 65% of college students indulge in binge drinking.

D. About 65% of college students indulged in binge drinking in the past month

A homeowner put a brand-name fertilizer/weed killer on half of his lawn and a generic fertilizer/weed killer on the other half. After three weeks, the generic side had 1 weed per square meter, the other side 1.7 weeds per square meter. The generic side required two mowings in the 3 weeks, the brand-name side one. The homeowner concluded that the generic was superior to the brand-name. Determine which evaluation guideline applies best in questioning the results of the described study.

A. Consider possible confounding variables.

B. Consider the sample.

C. Consider the type of study.

D. Consider the source.

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

12. Suppose that the cost of a statistics text was $50 in 1985 and is $100 in 2000. What is the ‘Statistics Text Index’ number, rounded to the nearest tenth, for the 2000 edition with the 1985 price as the reference value?

A. 20.0

B. 200.0

C. 50.0

D. 2.0

13. 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.

14. Convert 13% to decimal form.

A. 0.013

B. 0.13

C. 1.3

D. 13

15. 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

16. Soft drink sizes: small, medium, large:

A. Qualitative, nominal

B. Quantitative, ordinal

C. Quantitative, ordinal, discrete

D. Qualitative, ordinal

17. A sample consists of every 49th student from a group of 496 students. Identify the type of sampling used.

A. Systematic

B. Cluster

C. Convenience

D. Random

18. 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

19. To avoid working late, a quality control analyst simply inspects the first 100 items produced in a day. Identify the type of sampling used.

A. Stratified

B. Cluster

C. Convenience

D. Random

20. The father of a junior high school student wants to determine the most popular book among junior high students. Select the sample with the least potential bias.

A. A randomly selected group of 10 book sellers

B. A randomly selected group of 30 junior high students

C. A randomly selected group of 30 junior high students leaving the public library

D. The group of 30 junior high students attending the birthday party of the researcher’s child