collecting data practice
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Practice Day 6 Name___________________________Collecting Data Date_____________
Identify the population and the sample.1. A high school’s student newspaper plans to survey local businesses about the importance of students as
customers. From telephone book listings, the newspaper staff chooses 150 businesses at random. Of these, 73 return the questionnaire mailed by the staff.
2. A large retailer prepares its customers’ monthly credit card bills using an automatic machine that folds the bills, stuffs them into envelopes, and seals the envelopes for mailing. Are the envelopes completely sealed? Inspectors choose 40 envelopes from the 1000 stuffed each hour for visual inspection.
Identify if the following situations are an observational study or an experiment. Justify.3. An educator wants to compare the effectiveness of computer software for teaching mathematics with that of a
textbook presentation. She gives a math pretest to each of a group of high school juniors, then randomly divides them into two groups. One group uses the computer, and the other studies the text. At the end of the year, she tests all the students again and compares the increase in math test scores in the two groups.
4. A University of Helsinki study wanted to determine if chocolate consumption during pregnancy had an effect on infant temperament at age 6 months. Researchers began by asking 305 healthy pregnant women to report their chocolate consumption. Six months after birth, the researchers asked mothers to rate their infants’ temperament, including smiling, laughing, and fear.
Determine whether each situation would produce a random unbiased sample. Explain your answer.
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