Statistics and Probability Answers

he distances in kilometres travelled to work by employees of a city council may be modelled by a normal distribution with mean 75 and standard deviation of 2.5. Find the probability distance travelled to work by a random selected employee of the city council is a) less than 11km b)between 5.5km and 10.5km c)Find d such that 10% of the council’s employees travel less than d kilometers to work.

A discrete random variable has pmf P(X=n)=(1/2)^n. Let Y={1, if x is even and -1 if x is odd

Find the expected value of Y.

In a certain algebra 2 class of 29 students 18 of them play basketball in five them play baseball there are nine students who play neither sport what is the probability the student shows in a randomly from the class plays basketball or baseball

A student has to take 9 more courses before he can graduate. If none of the courses are prerequisite to others, how many groups of four courses can he select for the next semester?

at the fair you win $100 if you ring the loop on the hook. if not you win $0 the probability is very low at 2% chance determine how much you will expect to win in one try?

1. How effective is gastric bypass surgery in maintaining weight loss in extremely obese people? A Utah-based study conducted between 2000 and 2011 found that 76% of 418 subjects who had received gastric bypass surgery maintained at least a 20% weight loss six years after surgery.
a. Calculate a 90% confidence interval for the proportion of those receiving gastric bypass surgeries that maintained at least a 20% weight loss six years after surgery. (4 pts)
b. Interpret your interval in the context of the problem – what does the confidence interval mean in regards to this problem?

(a) An insurance salesman sells policies to 5 men, all of identical age in good health.
According to the actuarial tables the probability that a man of this particular age will be
alive 30years hence is 2
3
. Find the probability that in 30 years
(i) All men will be alive
(ii) At least 3men will be alive
(iii) Only two men will be alive
(iv) At least 1 man will be alive

1. A survey of a sample of business students resulted in the following information regarding the genders of the individuals and their selected major.

Selected Major

Gender Management Marketing Others Total
Male 40 10 30 80
Female 30 20 70 120
Total 70 30 100 200

a. What is the probability of selecting an individual who is majoring in Marketing?
b. What is the probability of selecting an individual who is majoring in Management, given that the person is female?
c. Given that a person is male, what is the probability that he is majoring in Management?
d. What is the probability of selecting a male individual?

What are the mean and standard deviation of the binomial distribution used in (a) through (c)? Interpret these values. In a survey
conducted by the Society for Human Resource Management, 68% of workers said that employers have the right to monitor their
telephone use. ( Snapshots, usatoday.com, April 18, 2006). Suppose that a random sample of 20 workers is selected, and they are
asked if employers have the right to monitor telephone use. What is the probability that:
a. 5 or less of the workers agree?
b. 10 or less of the workers agree?
c. 15 or less of the workers agree?

The average of 71, 22, 19, 74 and another number is 43. What is the other number?