Module 9 Final Exam Review Homework

When testing a new treatment, what is the difference between statistical significance and practical significance? Can a treatment have statistical significance, but not practical significance? Choose the correct answer below. A. Statistical significance is achieved when the result is very unlikely to occur by chance. Practical significance is related to whether common sense suggests that the treatment makes enough of a difference to justify its use. It is possible for a treatment to have statistical significance, but not practical significance. B. Statistical significance is related to whether common sense suggests that the treatment makes enough of a difference to justify its use. Practical significance is achieved when the result is very unlikely to occur by chance. It is not possible for a treatment to have statistical significance, but not practical significance. C. Statistical significance is achieved when the result is very unlikely to occur by chance. Practical significance is related to whether common sense suggests that the treatment makes enough of a difference to justify its use. It is not possible for a treatment to have statistical significance, but not practical significance. D. Statistical significance is related to whether common sense suggests that the treatment makes enough of a difference to justify its use. Practical significance is achieved when the result is very unlikely to occur by chance. It is possible for a treatment to have statistical significance, but not practical significance. 2. What is the goal of learning statistics? Choose the correct answer below. A. To learn to distinguish between statistical conclusions that are likely to be valid and those that are seriously flawed B. To use voluntary response samples to imply results about the population C. To use statistics for deception D. To accept the source of the data blindly 3. Determine whether the given value is a statistic or a parameter. In a study of all 1018 seniors at a college, it is found that 25% own a television. Choose the correct statement below. Statistic because the value is a numerical measurement describing a characteristic of a sample. Parameter because the value is a numerical measurement describing a characteristic of a population. Statistic because the value is a numerical measurement describing a characteristic of a population. Parameter because the value is a numerical measurement describing a characteristic of a sample. 4. Determine which of the four levels of measurement (nominal, ordinal, interval, ratio) is most appropriate for the data below. Mood levels of "happy," "alright," and "sad" Choose the correct answer below. A. The ordinal level of measurement is most appropriate because the data can be ordered, but differences (obtained by subtraction) cannot be found or are meaningless. B. The interval level of measurement is most appropriate because the data can be ordered, differences (obtained by subtraction) can be found and are meaningful, and there is no natural starting point. C. The ratio level of measurement is most appropriate because the data can be ordered, differences (obtained by subtraction) can be found and are meaningful, and there is a natural starting point. D. The nominal level of measurement is most appropriate because the data cannot be ordered. 5. Identify the type of sampling used (random, systematic, convenience, stratified, or cluster sampling) in the situation described below. In a poll conducted by a certain research center, 1222 adults were called after their telephone numbers were randomly generated by a computer, and 3% were able to correctly identify the attorney general. Which type of sampling did the research center use? Convenience sampling Systematic sampling Cluster sampling Stratified sampling Random sampling 6. Among fatal plane crashes that occurred during the past 70 years, 596 were due to pilot error, 81 were due to other human error, 375 were due to weather, 540 were due to mechanical problems, and 70 were due to sabotage. Construct the relative frequency distribution. What is the most serious threat to aviation safety, and can anything be done about it? Complete the relative frequency distribution below. Cause Relative Frequency Pilot error 35.9 % Other human error 4.9 % Weather 22.6 % Mechanical problems 32.5 % Sabotage 4.2 % (Round to one decimal place as needed.) What is the most serious threat to aviation safety, and can anything be done about it? A. Pilot error is the most serious threat to aviation safety. Pilots could be better trained. B. Mechanical problems are the most serious threat to aviation safety. New planes could be better engineered. C. Sabotage is the most serious threat to aviation safety. Airport security could be increased. D. Weather is the most serious threat to aviation safety. Weather monitoring systems could be improved. 7. Use the given categorical data to construct the relative frequency distribution. Natural births randomly selected from four hospitals in a highly populated region occurred on the days of the week (in the order of Monday through Sunday) with the frequencies 54, 66, 68, 55, 58, 46, 53. Does it appear that such births occur on the days of the week with equal frequency? Construct the relative frequency distribution. Day Relative Frequency Monday 13.50 % Tuesday 16.50 % Wednesday 17 % Thursday 13.75 % Friday 14.50 % Saturday 11.50 % Sunday 13.25 % (Type integers or decimals. Round to two decimal places as needed.) Let the frequencies be substantially different if any frequency is at least twice any other frequency. Does it appear that these births occur on the days of the week with equal frequency? A. Yes, it appears that births occur on the days of the week with frequencies that are about the same. B. No, it appears that births occur on the days of the week with frequencies that are substantially different. C. Yes, it appears that births occur on the days of the week with frequencies that are exactly the same. D. It is impossible to determine with the given information. 8. Fill in the blank. are sample values that lie very far away from the majority of the other sample values. Outliers are sample values that lie very far away from the majority of the other sample values. 9. Fill in the blank. In a distribution, the frequency of a class is replaced with a proportion or percent. In a relative frequency distribution, the frequency of a class is replaced with a proportion or percent. 10. Heights of adult males are normally distributed. If a large sample of heights of adult males is randomly selected and the heights are illustrated in a histogram, what is the shape of that histogram? Choose the correct answer below. Longer tail to the right Uniform Bell-shaped Longer tail to the left