21. A survey by the National Retail Federation found that women spend on average $146.21 for the Christmas holidays. Assume the standard deviation is $29.44. Find the percentage of women who spend less than $165.00. Assume the variable is normally distributed A) 14% B) 24% C) 64% D) 74% E) None of the above 22. Each month, an American household generates an average of 28 pounds of newspaper for garbage or recycling. Assume the standard deviation is 2 pounds. If the data conforms to a normal distribution and a household is selected at random, the probability of its generating between 28 and 30 pounds per month is about A) 14% B) 24% C) 34% D) 44% E) None of the above 23. To qualify for a police academy, candidates must score in the top 20% on a general abilities test. The test has a mean of 200 and a standard deviation of 20. Find the lowest possible score to qualify. Assume the test scores are normally distributed A) 153 B) 183 C) 200 D) 217 E) none of the above 24. The mean life time of a wristwatch is 24 months, with a standard deviation of 4 months. If the distribution is normal, for how many months should a guarantee be made if the manufacturer does not want to exchange more than 5% of the watches? Assume the variable is normally distributed: A) 57 B) 47 C)37 D) 27 E 17 25. What is the name of rule theorem you used to solve number 21? A) Empirical Rule B) Chebycher's Theroem Standardization D) Law of Large Numbers E) Central Limit Theorem