Weights of pears sold at a supermarket follow a normal distribution with mean 195 grams

and standard deviation 40 grams.

11. What is the third quartile of weights of all pears sold at the supermarket?

(A) 225 grams (B) 215 grams (C) 218 grams (D) 236 grams (E) 222 grams

12. A random sample of five pears is selected. What is the probability that the total weight of the pears is greater than one kilogram (i.e. 1,000 grams)?

(A) 0.2795 (B) 0.3897 (C) 0.2451 (D) 0.3264 (E) 0.4129

Suppose it is known that 8% of males are colour blind. In a random sample of 500 males, what is the approximate probability that at least 10% of them are colour blind?

(A) 0.03 (B) 0.04 (C) 0.05 (D) 0.06 (E) 0.07

The next two questions (19 and 20) refer to the following:

We would like to estimate the true mean service time for all customers in a fast food restaurants drive-thru. The population standard deviation of service times is known to be 50 seconds. We would like to select a sample of drive-thru customers large enough to estimate the true mean service time to within 10 seconds with 98% confidence?

1. Whatsamplesizeisrequired?(A)97(B)104(C)118(D)125 (E) 136
3. What will be the length of the 98% confidence interval? (A) 10.0 (B) 18.7 (C) 20.0 (D) 23.2(E) 46.5