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What type Of study is this? (a) Census (b) Experiment (c) Voluntary Response Survey (d) Observational Study (e) Matched-Pairs Study 2. A politician is considering running for public office. He wants to measure his name recognition by doing a survey of voters in his district. Which of the following survey methods would produce unbiased results? (a) The politician stands in front of a grocery store in his district on Saturday morning and asks each person entering the store if he or she recognizes the politician’s name. B) Placing pollsters in front of every grocery store in his strict on Saturday morning and asking each person entering the store if he or she recognizes the politician’s name. (c) Sending a survey card to all registered voters in the district asking them to call a phone number to state whether or not they recognize the politician’s name. (d) Calling people in the district listed in the phone book and asking each if he or she recognizes the politician’s name. (e) None of these methods would produce unbiased results. 3. A new headache remedy was given to a group of 25 subjects who had headaches.
Four hours after taking the new remedy, 20 of the subjects ported that their headaches had disappeared. From this information, you conclude: (a) that the remedy is effective for the treatment of headaches. (b) nothing, because the sample size is too small. (c) nothing because there is no control group for comparison. (d) that the new treatment if better than aspirin. (e) that the remedy is not effective for the treatment of headaches. 4. A nutritionist wants to study the effect of food storage time (6, 12, and 18 months) on the amount of Vitamin C present in freeze dried fruit when stored for these lengths of time.
Vitamin C is measured in milliards per 100 legalisms of fruit. Six fruit packs were randomly assigned to each of the three storage times. The treatment, experimental unit, and response are respectively: (a) a specific storage time, amount of Vitamin C, a fruit pack (b) a fruit pack, amount of Vitamin C, a specific storage time (c) random assignment, a fruit pack, amount of Vitamin C (d) a specific storage time, a fruit pack, amount of Vitamin C (e) a specific storage time, the nutritionist, amount of Vitamin C 5.
A researcher wishes to compare the effects of 2 fertilizers on the yield of a soybean crop. She has 20 plots of land available and she decides to use a aired experiment – using 10 pairs of plots. Thus, she will: (a) use a table of random numbers to divide the 20 plots into 10 pairs and then, for each pair, flip a coin to assign the fertilizers to the 2 plots. (b) subjectively divide the 20 plots into 10 pairs (making the plots within a block as similar as possible) and then, for each pair, flip a coin to assign the fertilizers to the 2 plots. C) use a table of random numbers to divide the 20 plots into 10 pairs and then use the table of random numbers a second time to decide upon the fertilizer to be applied to each pair. (d) flip a coin to divide he 20 plots into 10 pairs and then, for each pair, use a table of random numbers to assign the fertilizers to the 2 plots. (e) use a table of random numbers to assign the 2 fertilizers to the 20 plots and then use the table of random numbers a second time to place the plots into 10 pairs. 6. An experiment was designed to investigate the effect of the seed variety and amount of water upon subsequent growth of plants.
Each plant was potted in a clay plot, and a measured amount of water was given weekly. The height of the plant at the end of the experiment was measured. Which of the allowing is NOT correct? (a) The response variable is the plant height. (b) The explanatory variables are the amount Of water and seed variety. (c) Randomization was used to eliminate the effect of other possible factors upon the growth of plants. (d) A possible uncontrollable factor in the experiment is any nutrients that might be present in the clay plots. E) Designed experiments give the best evidence of “cause-and-effect” relationships. 7. A garage door manufacturer has developed a new type of door for houses in the Southeast part of the United States. Doors in this area of the country re particularly susceptible to damage from salty ocean spray and the sun’s rays, which tend to shine mainly on the north side of the house. An experiment will test the new type of garage door against the existing type of door on eight houses in a particular residential area. An overhead view of the area is shown below.