You have graduated from college and have been working hard to get established in your field. You eventually land a perfect job where you make tons of money. You decide to step up from the 1992 Chevrolet Cavalier that you have been nurturing for a number of years into a more "comfortable" car (a.k.a. more expensive). You decide to give your nephew who just got his drivers license the Cavalier; however, it needs a little work. You do some research and find out that the mean amount of time it takes a mechanic to rebuild a Cavalier transmission is 8.4 hours and a standard deviation of 1.8 hours. Judy warned you in her statistics class that you would never be the same after taking that class. You find yourself thinking...If 40 mechanics are randomly selected, what is the probability that their mean rebuild time exceeds 8.1 hours?
a. 0.8531
b. 0.7285
c. 0.8457
d. 0.9146

Solution Preview

Mean = 8.4
SD = 1.8
N = 40
First, Standard error is SE = SD / ...

Solution Summary

This shows how to find the probability that the mean exceeds a given number.

For a certain animal species, theprobability that a female will have a certain number of offspring in a given year is given in the table below. Findthe expected number of offspring per year.
Number of Offspring: 0
Probability: 0.31
Number of Offspring: 1
Probability: 0.21
Number of Offspring: 2
Probability: 0.19

Consider a Poisson probability distribution with 2 as the average number of occurrences per time period.
a. Write the appropriate Poisson probability function.
b. What is the average number of occurrences in three time periods?
c. Write the appropriate Poisson probability function to determinate theprobability of x occurren

Students in a class take a quiz with eight questions. Thenumber x of questions answered correctly can be approximated by the following probability distribution. Complete parts (a) through (e).
X 0 1 2 3 4 5 6 7 8
P(x) 0.02 0.04 0.05 0.05 0.11 0.24

5. A frequency distribution is shown below. Complete parts (a) through (e).
Thenumber of dogs per household in a small town
Dogs 0 1 2 3 4 5
Households 1261 438 169 46 27 11
(a) Use the frequency distribution to construct a probability distribution.
(b) Findthemean of theprobability distribution.
(c) Findthe variance

Please help with the following problem.
Compute the probabilities for each of the following when you throw five six-handed dice.
1) What is theprobability that all five have different numbers?
2) What is theprobability that at least four are the same?
3) What is theprobability that exactly three are sixes?

The random variable X is thenumber of houses per month sold by a realtor. Theprobability distribution is given below. Findthemean and standard deviation of X:
X (houses sold) / f(x)
____________________________________________
(0 , 0.24)
(1 , 0.01)
(2 , 0.12)
(3

What are the steps for using the Normal Table to findthe following:
a. TheProbability steps for (z<-2.65)
b. The Probability (z>-1.55)
c. TheProbability (-2.00TheProbability (1.25

The accompanying table describes results from eight offspring peas. The random variable x represents thenumber of offspring peas with green pods.
Table
Probabilities of Numbers of Peas with
Green Pods Among 8 Offspring Peas
x(Number of Peas with Green Pods) P(x)
0

A roulette wheel contains the integers 1 through 36, 0, 00. Suppose that you spin the wheel 6 times and that each time you bet on a single number. What is theprobability (rounded to nearest 100th) that you win on at least one bet?
Possible answers: 0.09, 0.11, 0.13, 0.15, none of the above.