Statistics and Probability Answers

Suppose the average number of car accidents on the highway in one day is 4.
(i) What is the probability of no car accident in one day?
(ii) What is the probability of 1 car accident in one day?
4. Suppose the average number of calls received by an operator in one minute is 2. What is
the probability of receiving 10 calls in one minute

The manager of the lodge has found that about 10% of the parties who make reservations
do not show up. If 120 party observations have been made,
(i) How many can be expected to show up?
(ii) Find the variance of this distribution.
(iii) Find the standard deviation of this distribution.

Suppose that 100 items are drawn from a population of manufactured products and the weight, X, of each item is recorded. Prior experience has shown that the weight has a non-normal probability distribution with  = 8 ounces and  = 3 ounces. Consider the sampling distribution of the sample mean of the weights .


a. Can you describe the sampling distribution of the sample mean? Explain why.

b. Find the mean and variance of the sample mean?

c. Find the probability that the mean weight is greater than 8 ounces.
d. Find the probability that the mean weight is less than 6 ounces.
e. Find the probability that the mean weight is between 7 ounces and 9 ounces

After the political ad​ campaign, pollsters check the prime minister​'s negatives. They test the hypothesis that the ads produced no change against the alternative that the negatives are now below 54​% and find a​ P-value of 0.089. Which conclusion is​ appropriate? Explain.
Choose the correct answer below.
There is a 8.9​% chance that natural sampling variation could produce poll results at least as far below 54​% as these if there is really no change in public opinion.
B.
There is a 8.9​% chance that the poll they conducted is correct.
C.
There is a 8.9​% chance that the ads worked.
D.
There is a 91.1​% chance that the ads worked.

According to the Sleep Foundation, the average night’s sleep is 7 hours. Assume the standard deviation is 0.5 hours and that the probability distribution is normal.

a. What is the probability that a randomly selected person sleeps more than 9 hours?

b. What is the probability that a randomly selected person sleeps 5 hours or less?

c. What is the probability that a randomly selected person sleeps exactly 10 hours?

d. What is the probability that a randomly selected person sleeps more than 7 hours?

e. Doctors suggest getting between 7 and 9 hours of sleep each night. What percentage of the population gets this much sleep?

How did you get the 1/1 in the shuffled of kings question

In a sample of 1000 people in Ambedkar Nagar, 540 are rice eaters
and the rest are wheat eaters. can we assume that both rice and
wheat are equally popular in this district at 1% level of significance?

A ball is drawn at random from a box containing 10 red balls, 30 white balls, 20 blue balls and 15 black balls.Obtain the probability that the ball drawn is:
(1)black or red
(2) not red or blue
(3)not blue
(4) white
(5) red, white,blue

4. To determine the average amount of purchases of its customers, a convenience store samples 150 of its customers. The average purchase of the group is Php 125. If the store knew that the standard deviation of all purchase is Php 50, what is the 95% confidence interval for the average purchase in the store?

The breaking strengths of cables produced by a manufacturer have mean 1800 lb and standard deviation 100 lb. By a new technique in the manufacturing process it is claimed that the breaking strength can be increased. To test the claim, a sample of 50 cables is tested, and it is found that the mean breaking strength is 1850 lb. (a) Can you support the claim at 0.01 level of significance? (b) What is the P value of the test?