Questions from Business Statistics

Q: You have just performed a survey interviewing 358 randomly selected people.

You have just performed a survey interviewing 358 randomly selected people. You found that 94 of them are interested in possibly purchasing a new cable TV service. How much uncertainty is there in thi...

Q: You are planning to make sales calls at eight firms today.

You are planning to make sales calls at eight firms today. As a rough approximation, you figure that each call has a 20% chance of resulting in a sale and that firms make their buying decisions withou...

Q: Suppose that the number of hits on your company’s website, from

Suppose that the number of hits on your company’s website, from noon to 01:00 pm on a typical weekday, follows a normal distribution (approximately) with a mean of 190 and a standard deviation of 24....

Q: Find the probability that you will see moderate improvement in productivity,

Find the probability that you will see moderate improvement in productivity, meaning an increase in productivity between 6 and 13. You may assume that the productivity increase follows a normal distri...

Q: For the experience variable: Answer the parts of exercise 2.

For the experience variable: Answer the parts of exercise 2. Data from exercise 2: For the annual salary levels: a. Construct a cumulative distribution function. b. Find the median, quartiles, and e...

Q: Under usual conditions, a distillation unit in a refinery can process

Under usual conditions, a distillation unit in a refinery can process a mean of 135,000 barrels per day of crude petroleum, with a standard deviation of 6,000 barrels per day. You may assume a normal...

Q: The quality control section of a purchasing contract for valves specifies that

The quality control section of a purchasing contract for valves specifies that the diameter must be between 2.53 and 2.57 cm. Assume that the production equipment is set so that the mean diameter is 2...

Q: Assume that the stock market closed at 13,246 points today

Assume that the stock market closed at 13,246 points today. Tomorrow you expect the market to rise a mean of four points, with a standard deviation of 115 points. Assume a normal distribution. a. Find...

Q: Based on recent experience, you expect this Saturday’s total receipts to

Based on recent experience, you expect this Saturday’s total receipts to have a mean of $2,353.25 and a standard deviation of $291.63 and to be normally distributed. a. Find the probability of a typic...

Q: The amount of ore (in tons) in a segment of

The amount of ore (in tons) in a segment of a mine is assumed to follow a normal distribution with mean 185 and standard deviation 40. Find the probability that the amount of ore is less than 175 tons...