A state university found that it retained 25 students out of 352 in 2003 and 26 students out of 334 ...

A state university found that it retained 25 students out of 352 in 2003 and 26 students out of 334 in 2004. Construct a 90 confidence interval for the difference in the proportions of students retained in 2003 and 2004.
 
  A) -0.0535 to 0.0398 B) -0.0461 to 0.0325 C) -0.0585 to 0.0449 D) -0.0398 to 0.0262

Q. 2

The annual precipitation for one city is normally distributed with a mean of 274 inches and a standard deviation of 3.9 inches. Fill in the blanks.
 
  In 95.44 of the years, the precipitation in this city is between ___ and ___ inches.
 
  A) 266.2, 281.8 B) 274, 281.8 C) 262.3, 274 D) 262.3, 285.7

Q. 3

In a random sample of 300 women, 67 favored stricter gun control legislation. In a random sample of 200 men, 59 favored stricter gun control legislation.
 
  Construct a 98 confidence interval for the difference between the proportions of women and men who favor stricter gun control legislation.
  A) -0.010 to 0.170 B) -0.034 to 0.194 C) -0.006 to 0.166 D) -0.023 to 0.183

Q. 4

The amount of Jen's monthly phone bill is normally distributed with a mean of 64 and a standard deviation of . Fill in the blanks.
 
  68.26 of her phone bills are between ___ and ___.
 
  A) 64, 76 B) 40, 64 C) 40, 88 D) 52, 76

Q. 5

A market researcher randomly selects 400 homeowners under 35 years of age and 100 homeowners over 35 years of age. What sampling technique was used?
 
  A) simple random
  B) convenience
  C) systematic
  D) cluster
  E) stratified

Q. 6

The amount of Jen's monthly phone bill is normally distributed with a mean of 75 and a standard deviation of . What percentage of her phone bills are between 42 and 108?
 
  A) 99.74 B) 68.26 C) 95.44 D) 99.99

Q. 7

The book cost (in dollars) for one semester's books are given below for a sample of five college students. Calculate the sample variance of the book costs.
   225, 140, 415, 485, 285
 
  A) 345.00 B) 310.00 C) 140.00 D) 19,600.00

Q. 8

The tread life of a particular brand of tire is a random variable best described by a normal distribution with a mean of 60,000 miles and a standard deviation of 2800 miles.
 
  What warranty should the company use if they want 96 of the tires to outlast the warranty?
  A) 64,900 mi B) 57,200 mi C) 62,800 mi D) 55,100 mi