Complete the mcq:
Q1. In 1999, the average charge for tax preparation by H&R Block, Inc. was $84.57. Assuming a normal distribution and a standard deviation of 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?
Q2. For the normal distribution described what is the probability that a randomly selected tax preparation customer would have paid a fee
a. between $70 and $80?
b. under $60? c. over $90?
Q3. 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)?
Q4. A random variable is Poisson distributed with alpha = 0.50 arrivals per minute. For the corresponding exponential distribution, and x= minutes until the next arrival, identify the mean of x and determine the following:
a. P(x
b. P( x
c. P( x >or_ 2.5)
d. P( x >or_ 3.0)