Question

. An automotive repair shop has determined that the average service time on an automobile is...

. An automotive repair shop has determined that the average service time on an automobile is 2 hours with a standard deviation of 32 minutes. A random sample of 64 services is selected.

a.

What is the probability that the sample of 64 will have a mean service time greater than 114 minutes?

b.

Assume the population consists of 400 services. Determine the standard error of the mean.

                                                                                                                                                                                 

Homework Answers

Answer #1

Solution :

(a)

= / n = 32 / 64 = 4

P( > 114) = 1 - P( < 114)

= 1 - P[( - ) / < (114 - 120) / 4]

= 1 - P(z < -1.5)

= 0.9332

(b)

Standard error = / n = 32 / 400 = 1.6

Know the answer?
Your Answer:

Post as a guest

Your Name:

What's your source?

Earn Coins

Coins can be redeemed for fabulous gifts.

Not the answer you're looking for?
Ask your own homework help question
Similar Questions
The time required for an automotive center to complete an oil change service on an automobile...
The time required for an automotive center to complete an oil change service on an automobile approximately follows a normal​ distribution, with a mean of 19 minutes and a standard deviation of 3.5 minutes. ​(a) The automotive center guarantees customers that the service will take no longer than 20 minutes. If it does take​ longer, the customer will receive the service for​ half-price. What percent of customers receive the service for​ half-price? ​(b) If the automotive center does not want...
The time required for an automotive center to complete an oil change service on an automobile...
The time required for an automotive center to complete an oil change service on an automobile approximately follows a normal​ distribution, with a mean of19 minutes and a standard deviation of 4 minutes. ​(a) The automotive center guarantees customers that the service will take no longer than 20 minutes. If it does take​ longer, the customer will receive the service for​ half-price. What percent of customers receive the service for​ half-price? ​(b) If the automotive center does not want to...
The time required for an automotive center to complete an oil change service on an automobile...
The time required for an automotive center to complete an oil change service on an automobile approximately follows a normal​ distribution, with a mean of 19 minutes and a standard deviation of 3.5 minutes. ​(a) The automotive center guarantees customers that the service will take no longer than 20 minutes. If it does take​ longer, the customer will receive the service for​ half-price. What percent of customers receive the service for​ half-price? ​(b) If the automotive center does not want...
The time required for an automotive center to complete an oil change service on an automobile...
The time required for an automotive center to complete an oil change service on an automobile approximately follows a normal​ distribution, with a mean of 15 minutes and a standard deviation of 3.5 minutes. (A)The automotive center guarantees customers that the service will take no longer than 20 minutes. If it does take​ longer, the customer will receive the service for​ half-price. What percent of customers receive the service for​ half-price? (B) If the automotive center does not want to...
The time required for an automotive center to complete an oil change service on an automobile...
The time required for an automotive center to complete an oil change service on an automobile approximately follows a normal​ distribution, with a mean of 15 minutes and a standard deviation of 4 minutes. ​(a) The automotive center guarantees customers that the service will take no longer than 20 minutes. If it does take​ longer, the customer will receive the service for​ half-price. What percent of customers receive the service for​ half-price? ​(b) If the automotive center does not want...
.A year-old study found that the service time for all drive-thru customers at the Stardust Coffee...
.A year-old study found that the service time for all drive-thru customers at the Stardust Coffee Shop is uniformly distributed between 3 and 6 minutes. Assuming the service time distribution has not changed, a random sample of 49 customers is taken and the service time for each is recorded. a. Calculate the mean and standard deviation of service times for all drive-thru customers at the Stardust Coffee Shop. (Hint: Review the uniform distribution from Chapter 6.) b. What is the...
The owner of a computer repair shop has determined that their daily revenue has mean $7200...
The owner of a computer repair shop has determined that their daily revenue has mean $7200 and standard deviation $1200. The daily revenue is normally distributed. a) What is the probability that a randomly selected day will have a revenue of at most $7000? b) The daily revenue for the next 30 days will be monitored. What is the probability that the mean daily revenue for the next 30 days will exceed $7500?
Suppose that the population average for weekly earnings for employees in general automotive repair shops is...
Suppose that the population average for weekly earnings for employees in general automotive repair shops is $450, and that the population standard deviation for the earnings for such employees is $50. A sample of 100 such employees is selected at random. 16) What is the probability distribution of the average weekly earnings of a sample of 100 for employees in general automotive repair shops? a) Normal b) Not enough information to determine c) t-distributed. d) None of the above 17)...
The owner of a computer repair shop has determined that their daily revenue has mean $7200...
The owner of a computer repair shop has determined that their daily revenue has mean $7200 and standard deviation $1200. The daily revenue totals for the next 30 days will be monitored. What is the probability that the mean daily revenue for the next 30 days will exceed $7500?
The owner of a computer repair shop has determined that their daily revenue has mean​ $7200...
The owner of a computer repair shop has determined that their daily revenue has mean​ $7200 and standard deviation​ $1200. The daily revenue totals for the next 30 days will be monitored. What is the probability that the mean daily revenue for the next 30 days will be between​ $7000 and​ $7500? Round to four decimal places.