The length of time it takes college students to find a parking spot in the library parking lot follows a normal distribution with a mean of 4.5 minutes and a standard deviation of 1 minute.
Find the probability that a randomly selected college student will take between 3.0 and 5.5 minutes to find a parking spot in the library lot.
A) 0.2255 B) 0.4938 C) 0.0919 D) 0.7745
Q. 2A senator wishes to estimate the proportion of United States voters who favor abolishing the Electoral College.
How large a sample is needed in order to be 98 confident that the sample proportion will not differ from the true proportion by more than 6?
A) 378 B) 10 C) 755 D) 267
Q. 3A manager asked her employees how many times they had given blood in the last year. The results of the survey are given below.
The random variable x represents the number of times a person gave blood and P(x) represents the probability of selecting an employee who had given blood that percent of the time. What is the mean number of times a person gave blood based on this survey?
x 0 1 2 3 4 5 6
P(x) 0.30 0.25 0.20 0.12 0.07 0.04 0.02
A) 3.0 B) 2.0 C) 1.6 D) 0.14
Q. 4A researcher randomly selected 100 adults aged 18-25 and 100 adults aged 50-60. Within each age group, she recorded the number of smokers.
A) qualitative, dependent B) qualitative, independent
C) quantitative, independent D) quantitative, dependent
Q. 5The length of time it takes college students to find a parking spot in the library parking lot follows a normal distribution with a mean of 3.0 minutes and a standard deviation of 1 minute.
Find the probability that a randomly selected college student will find a parking spot in the library parking lot in less than 2.5 minutes.
A) 0.1915 B) 0.3551 C) 0.3085 D) 0.2674
Q. 6Identify the response variable.
What will be an ideal response?
Q. 7A researcher at a major clinic wishes to estimate the proportion of the adult population of the United States that has sleep deprivation.
How large a sample is needed in order to be 99 confident that the sample proportion will not differ from the true proportion by more than 5?
A) 543 B) 13 C) 1327 D) 664
Q. 8A city council randomly selects 1000 married couples from a certain city and records the number of women who are in favor of a new football stadium and the number of men who are in favor.
A) qualitative, independent B) quantitative, independent
C) quantitative, dependent D) qualitative, dependent
Q. 9The level of significance, , is the probability of making a
A) Correct decision B) Type II error C) Type error D) Type I error