In 1999, the average charge for tax preparation by H&R Block, Inc. was $84.57. Assuming a normal distribution

and a standard deviationof o = $10, what proportion of H&R Block’s tax preparation fees were.

a. more than $84.57?

b. between $64.57 and $104.57?

c. between $74.57 and $94.57?

d. more than $104.57?

2. For the normal distributiondescribed in Exercise

1, what is the probabilitythat a randomly selected

tax preparation customer would have paid a fee

a. between $70 and $80?

b. under $60? c. over $90?

3. It has been reported that households in the West

spend an annual average of $6050 for groceries. Assume

a normal distribution with a standard deviation of

$1,500.00

a. What is the probability that a randomly selected Western

household spends more than $6350 for groceries?

b. How much money would a Western household have

to spend on groceries per year in order to be at the

99th percentile(i.e., only 1% of Western households

would spend more on groceries)?

4. A random variableis Poissondistributed with

alpha = 0.50 arrivals per minute. For the corresponding exponential

distribution, and x= minutes until the next arrival,

identify the meanof x and determine the following:

a. P(x <or_ 0.5)

b. P( x <or _ 1.5)

c. P( x >or_ 2.5)

d. P( x >or_ 3.0)

This solution determines the proportion of tax preparation fees that H&R Block Inc. will accumulate.