Question

1. An official has observed that his accounts are paid on average in 50 days, with a standard deviation of 10 days. Using the Empirical Rule, and assuming a normally distributed number of days, estimate what proportion of the accounts will be paid between 60 and 70 days: *

(A) 13.5%

(B) 32%

(C) 68%

(D) 95%

2. Suppose we have a bell-shaped, symmetrical distribution, and then we add some extreme outlier points to the right tail. Which of the following will now be true?: *

(A) Mode > Mean > Median

(B) Median > Mode > Mean

(C) Mean > Median > Mode

(D) Mode > Median > Mean

Questions 3-4: The daily high temperature for Chattanooga is normally distributed with mean 79 and standard deviation 4.

3. What is the upper quartile for this population?: *

(A) 79.5

(B) 80.5

(C) 81.7

(D) 82.4

4. Find the probability that a randomly chosen temperature is between 70 and 75: *

(A) 0.0122

(B) 0.1464

(C) 0.1587

(D) 0.8413

Answer 1