Statistics and Probability Answers

The mean grade point average for statistical inference I course in a particular session is 2.45 with variance of 0.4761 it is believed that statistics majors have higher grade point average than the overall mean. A sample of 100 statistics major had a mean grade point average of 2.65. Test his claim at 1% level of significance

A family has two dogs (Rex and Rover) and a cat called Garfield. None of them is fond of the postman. If

they are outside, the probability that Rex, Rover and Garfield will attack the postman are 30%, 40% and

15%, respectively. Only one is outside at time, with probabilities 10%, 20% and 70%, respectively.

If the postman is attacked, what is the probability that Rex was the culprit?

A box contains 5 balls. Two are numbered 1, one is numbered 2, and two are numbered 3. The balls are mixed and one is selected at random. After a ball is selected, its number is recorded. Then it is replaced. If the experiment is repeated many times, find the mean, variance, and standard deviation of the numbers on the balls.

Denote by [x] the greatest integer not exceeding x. For the pdf in Example 2.2.1, show

that the CDF can be represented as F(x) = ([x]/12)2 for O < z < 13, zero if x O, and

one ifx13.

Determine the value c so that each of the following functions can serve as a probability distribution of the discrete random variable X: (b) f(x) = c (2 ) (3 )

( assume 2 & x in same parentheses and 3&3-x) ( x ) (3 - x) , for x = 0, 1, 2

listed below are foot lengths in inches for 11 randomly selected people taken in 1968. find the range, variance, and standard deviation for the given sample data. include apropriate units in the results. are the statistics representative of the current population of all people? 10.1, 9.9, 9.1, 9, 9.9, 10.3, 9.3, 10.4, 9.7, 9.8

A number is selected randomly from a container containing all the integers from 10 to 50. Find P(Prime between 11 and 30).

A part is randomly selected during a quality assurance test and is found to be defective. Calculate the probability that it was supplied by supplier B

The following are number of words per minute typef by 4 secretaried on 4 different typewriter models(ROYAL,IBM,UNDERWOOD,OLIVETRI)

Secretary

Kim ROYAL78..OLIVETRI 77

Doug ROYAL 57...OLIVETRI 60

Rhonda ROYAL 69...OLIVETRI83

Kevin ROYAL 71...OLEVITRI 67

KIM IBM 62...UNDERWOOD 71

DOUG IBM 49..UNDERWOOD 62

Rhonda IBM 78..UNDERWOOD 72

KEVIN IBM 66..UNDERWOOD 59

USE 0.05 LEVEL OF SIGNIFICANCE TO TEST THE HYPOTHESIS

a. The secretaries type with equal speed.

b. Different typewriters have no effect typing speed.

In all fours, 6 cards are dealt from a 52-card deck to each of 4 players and then

a card is dealt face up to determine the trump suit. The four players form two teams of two

players each. Suppose that a 10 of clubs is dealt as the face up card. Suppose also, that the

first player was dealt with a Jack and 3 cards with ranks less than 10, of the trump suit.

What is the probability that the second player dealt gets the highest trump in the deck i.e.

Ace of clubs?