The mayor of one city has been conducting an anti-smoking campaign in high schools. Each year local government researchers estimate the number of teenagers in the city who smoke.
The number of smokers has declined steadily in each of the past five years. The mayor's office constructs a bar graph showing the number of teenage smokers in each of the past five years. If the mayor wished to exaggerate the success of his anti-smoking campaign, would it be to his advantage to truncate the bar graph? Explain your thinking.
Q. 2The average score of local students on a college entrance exam is 110, with a standard deviation of 5. The distribution is roughly bell shaped. Use the Empirical Rule to find the percentage of local students with scores above 120.
A) 97.5 B) 2.5 C) 5 D) 95
Q. 3What is a factor?
What will be an ideal response?
Q. 4Find the area under the standard normal curve between z = -1.25 and z = 1.25.
A) 0.8817 B) 0.2112 C) 0.7888 D) 0.6412
Determine the area under the standard normal curve that lies between:
Q. 5n = 133, x = 73; 90 level
A) 0.480 to 0.614 B) 0.476 to 0.618 C) 0.477 to 0.617 D) 0.481 to 0.613
Q. 6A variable is normally distributed with a mean of 100 and a standard deviation of 10. Which is larger, the percentage of observations between 80 and 90 or the percentage of observations between 120 and 130? Explain your reasoning.
What will be an ideal response?
Q. 7The scores from a state standardized test have a mean of 80 and a standard deviation of 10. The distribution of the scores is roughly bell shaped. Use the Empirical Rule to find the percentage of scores that lie between 60 and 80.
A) 47.5 B) 34 C) 68 D) 95
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