Stats-Distribution

Sample Statistics Questions 1. Dorothea conducted a survey to find out how many national parks people had visited in the past two years. She polled twenty people and found that ten people had visited no national parks; five people had visited one national park; four people had visited two national parks; and one person had visited twenty national parks. Which measure of central tendency should Dorothea use to provide the most accurate picture of her data? A) Mean B) Median C) Mode D) Standard deviation E) Analysis of variance

2. Abby, Chrissy, and Kate are teammates playing "Win, Lose, or Draw." They need exactly 10 points to win and must choose who will draw next. They have some statistics on the points each girl gets when she draws: Abby has a mean of 10 points, Chrissy has a median of 10 points, and Kate has a mode of 10 points. Which girl should draw to have the best chance of winning? A) Abby B) Chrissy C) Kate D) either Abby or Chrissy E) any of the three

3. Which of the following statements is false? A) The range is the difference between the highest and lowest scores. B) The mean is the arithmetic average. C) The mode is the most frequent score D) .There can be more than one mode in a data set. E) The median is one-half of the range.

4. A researcher measured the number of times each of 6 rats had to run a maze before it mastered the maze. The number of times recorded for each rat was 2,3,3,4,5, 7. In this example, the A) mean is smaller than the median. B) median is larger than the mode. C) mean is larger than the range. D) mode is larger than the range. E) mean, median, and mode are all the same.

5. To calculate the mean of a set of data you add up all the scores and divide the result by the A) range. B) standard deviation. C) number of scores. D) mode. E) median.

6. Consider the following data set: 2,2, 3, 3, 3, 4, 4, 5, 5, 92. if the last value (92) is removed from the data set, which of the following statistics will change the most? A) Mode B) Mean C) Median D) Mode and the mean E) Median and the mode

7. Batina is a conservative investor much to the chagrin of her husband. He cannot believe she values stability in an investment over the historical rate of return. The standard deviations of the following returns of investment are given below. Which investment should Batina choose? A) 1.23 B) 0.98 C) 2.21 D) 1.91 E) 2.55

8. Alejandra is interested in describing the spread of the scores in her data set. She should calculate the ___ of the data set. A) mean B) median C) correlation D) mode E) range

9. What does it mean if the standard deviation of a distribution of quiz grades is O? A) An equal number of people got each grade (A, B, C, D, and E). B) The distribution is a normal, bell-shaped curve. C) Everyone in the class got the same grade or score. D) Everyone in the class got a different grade. E) The test was likely too difficult for students to perform well.

10. In a normal distribution of scores, which of the following is true? A) About 5 percent of the scores are more than two standard deviations from the mean. B) The mean score is always O.. C) Most scores are located in the two "tails" at eitheiend of the distribution. D) The standard deviation indicates the arithmetic average score. E) The mean and median will be different.

11. Which of the following is a characteristic of a normal distribution? A) The mean and the standard deviation are equal. B) The standard deviation and the variance are equal. C) Fifty percent of the sample is within one standard deviation of the mean. D) The mean, median, and mode are equal. E) There is more than one mode.

12. Crystal received her SAT score from her counselor. She scored two standard deviations above the mean. This means that Crystal's score was A) higher than 97.5 percent of the other scores. B) only higher than 84 percent of the other scores. C) only higher than 68 percent of the other scores. D) only higher than 50 percent of the other scores. E) There is insufficient information to answer this question.

13. Joe has collected data on the number of hours ten-year-olds spend watching television each week. He tells you that the distribution of scores followed a truly normal curve. Which of the following is not suggested by Joe's statement? A) Fifty percent of the scores fall below the mean. B) The mean, median, and mode are the same value. C) Sixty-eight percent of the scores fall within one standard deviation above and below the mean. D) Ten percent of the scores fall two standard deviations above the mean. E) Fifty percent of the scores fall above the mean.

14. If an IQ test is constructed to have a mean of 100 and a standard deviation of 16, approximately what percentage of scores falls between 84 and 116? A) 34 percent B) 95 percent C) 68 percent D) 50 percent E) 99 percent

15 . You are conducting a survey of international students studying at your university. Several of the questions on the survey try to determine how much exposure to American culture the student had before coming to the US. You suspect that the more exposure the student had before arriving here, the fewer problems of adjustment he or she will report. You are looking for a(n) A) hypothesis. B) negative correlation. C) positive correlation. D) independent variable. E) operational definition.

16. Francesca is at a casino watching a game involving dice. She determines that one of the dice is loaded, causing it to turn up "3" more often than would be expected by chance. Her finding is said to have statistical A) reliability. B) power. C) validity. D) generalizability. E) significance.

17. In Dr. Dalbey's study, women missed an average of three workdays a year because of colds and men missed an average of five workdays because of colds. To see if the difference between these means is statistically significant, Dr. Dalbey should A) calculate a set of medians. B) calculate a correlation coefficient. C) conduct a t test. D) utilize factor analytic techniques. E) find the measure of central tendency.

For Normal/Bell curve see text page 36