A researcher wished to assess the importance of exercise in weight-loss programs. 412 people, all considered to be at least 20 pounds overweight, volunteered to participate in a study. The participants were randomly assigned to one of two groups.
Over a two-month period, the first group followed a particular diet but were instructed to perform no exercise other than walking. The second group followed the same diet but also performed aerobic exercise for one hour each day. At the end of the two months, the weight loss of each participant was recorded. The average weight loss was calculated for each group and it was found that the average weight loss for the second group was significantly greater than the average weight loss for the first group.
A) Designed experiment B) Observational study
Q. 2In a clinical trial, 780 participants suffering from high blood pressure were randomly assigned to one of three groups.
Over a one-month period, the first group received the experimental drug, the second group received a placebo, and the third group received no treatment. The diastolic blood pressure of each participant was measured at the beginning and at the end of the period and the change in blood pressure was recorded. The average change in blood pressure was calculated for each of the three groups and the three averages were compared.
A) Designed experiment B) Observational study
Q. 3An educational researcher used school records to determine that, in one school district, 84 of children living in two-parent homes graduated high school while 75 of children living in single-parent homes graduated high school.
A) Designed experiment B) Observational study
Q. 4At one hospital in 1992, 674 women were diagnosed with breast cancer. Five years later, 88 of the Caucasian women and 83 of the African American women were still alive.
A) Designed experiment B) Observational study
Q. 5In a competition, two people will be selected from four finalists to receive the first and second prizes. The prize winners will be selected by drawing names from a hat.
The names of the four finalists are Jim, George, Helen, and Maggie. The possible outcomes can be represented as follows.
JG JH JM GJ GH GM
HJ HG HM MJ MG MH
Here, for example, JG represents the outcome that Jim receives the first prize and George receives the second prize. List the outcomes that comprise the following event.
A = event that Helen gets a prize
A) JH, GH, HJ, HG, HM, MH B) JH, GH, HJ, HG, HM
C) HJ, HG, HM D) JH, GH, HJ, JG, HG, HM, MH
Q. 6The spell-checker in a desktop publishing application may not catch all misspellings (e.g. their, there) or correctly interpret the spellings of proper names. Jackie is an expert editor and can proofread extremely quickly.
Jackie is hired by a book publisher to check the spelling of every word in the latest proof of a history book. With regard to Jackie's assignment, what is the population?
A) The total number of misspellings that Jackie finds in the latest proof of the history book
B) The latest proof of the history book
C) Every word in the latest proof of the history book
D) Finding misspellings in the latest proof of the history book
Q. 7George, a network engineer, ordered 500 CAT 5e Ethernet cables for use at his company's network. After receiving these cables, he decided to randomly test 150 of these cables before using them.
He was alarmed to find out that 92 of these cables failed completely. He returned the entire lot to the manufacturer. When he tested the cables, what was George's sample?
A) 460 cables B) 500 cables C) 138 cables D) 150 cables
Q. 8Find the z-score corresponding to the given value and use the z-score to determine whether the value is unusual. Consider a score to be unusual if it is at least three standard deviations above or below the mean.
Round the z-score to one decimal place, if necessary.
A body temperature of 95.8 F given that human body temperatures have a mean of 98.20 F and a standard deviation of 0.62.
A) -3.8; unusual B) -2.4; not usual C) 3.8; not unusual D) -3.8; not unusual
Q. 9Find the z-score corresponding to the given value and use the z-score to determine whether the value is unusual. Consider a score to be unusual if it is at least three standard deviations above or below the mean.
Round the z-score to one decimal place, if necessary.
A test score of 91.0 on a test having a mean of 73 and a standard deviation of 10.
A) 18; unusual B) 1.8; not unusual C) -1.8; not unusual D) 1.8; unusual
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