The speed with which utility companies can resolve problems is very important. The Georgetown Telephone Company (GTC), reports that it can resolve customer problems the same day they are reported in 53% of the cases. Suppose that the 9 cases reported today are representative of all complaints.

a-1. How many of the problems would you expect to be resolved today? (Round the final answer to 2 decimal places.)

Number of Problems

a-2. What is the standard deviation? (Round the final answer to 4 decimal places.)

Standard Deviation

b. What is the probability that 4 of the problems can be resolved today? (Round the final answer to 4 decimal places.)

Probability

c. What is the probability that 4 or 5 of the problems can be resolved today? (Round the final answer to 4 decimal places.)

Probability

d. What is the probability that more than 4 of the problems can be resolved today? (Round the final answer to 4 decimal places.)

Probability

Steele Electronics Inc. sells expensive brands of stereo equipment in several shopping malls. The marketing research department of Steele reports that 27% of the customers entering the store that indicate they are browsing will, in the end, make a purchase. Let the last 17 customers who enter the store be a sample.

a. How many of these customers would you expect to make a purchase? (Round the final answer to the nearest whole number.)

Number of Customers

b. What is the probability that exactly five of these customers make a purchase? (Round the final answer to 4 decimal places.)

Probability

c. What is the probability 8 or more make a purchase? (Round the final answer to 4 decimal places.)

Probability

d. Does it seem likely at least one will make a purchase ("likely" refers if the probability is more than 70%)?

In a recent survey, 44% indicated chocolate was their favorite flavour of ice cream. Suppose that we select a sample of 15 people and ask them to name their favourite flavour of ice cream.

a. How many of those in the sample would you expect to name chocolate? (Round the final answer to 2 decimal place.)

Expected number of people

b. What is the probability exactly nine of those in the sample name chocolate? (Do not round the intermediate values. Round the final answer to 4 decimal places.)

Probability

c. What is the probability nine or more name chocolate? (Do not round the intermediate values. Round the final answer to 4 decimal places.)

Probability