Statistics and Probability Answers

for this linear regression line find y-intercept and slope

y=-24x+110

a survey of a track team concluded that they ran an average of 28miles a week with a standard deviation of 7miles per week. Approximately what percentage of runners in the club ran less than 30 miles per week?

The following data represent the number of units of production per day turned out by 5 different workmen using different types of machines.
Workmen Machine type
A B C D
1 44 38 47 36
2 46 40 52 43
3 34 36 44 32
4 43 38 46 33
5 38 42 49 39

i) Test whether the mean productivity is the same for the four different machine types.
ii) Test whether 5 men differ with respect to mean productivity.

probability qtn:
choose from 1st barrel : 5 out of 50 balls plus also then choose from a second barrel 2 out of 11 balls. Probability is = 50 X 49 X 48 X 47 X 46 X 11 X 10 = 27 billion but stated odds are 116 million......which is correct?

suppose it is estimated that a person visiting Florida will visit Disney World, Busch Gardens or both with probabilities 0.7, 0.1, and 0.2 respectively. Find the probability that a person visiting Florida will visit Busch Gardens given that the person did not visit DIsney World.

A family has three children.

Using b to stand for boy and g for girl give the following. (To indicate that the first child is a boy, the second child is a boy, and the third child is a girl enter bbg. Enter your answers as a comma-separated list.)

(a) the sample space
S =



(b) the event E that the family has exactly two daughters
E =


(c) the event F that the family has at least two daughters
F =


(d) the event G that the family has three daughters
G =


Give the following. (Assume that boys and girls are equally likely. Enter your probabilities as fractions.)

(e) p(E)


(f) p(F)

(g) p(G)


(h) o(E)


(i) o(F)


(j) o(G)

Let S be the event that a cell phone user switches carriers, and let D be the event that a cell phone user gets dropped a lot. Write the following probabilities and identify which are conditional and which are not conditional.

(a) The probability that a cell phone user switches carriers given that she gets dropped a lot.
p(S | D)
p(D | S)

p(S ∩ D)

Is the event conditional?
Yes No

(b) The probability that a cell phone user switches carriers and gets dropped a lot.
p(S | D)
p(D | S)

p(S ∩ D)

Is the event conditional?
Yes No

(c) The probability that a cell phone user gets dropped a lot given that she switches carriers.
p(S | D)
p(D | S)

p(S ∩ D)

Is the event conditional?
Yes No

Of all the DVDs in a large shipment, 20% have a defective disc, 16% have a defective case, and 10% have both defects. If you purchase one of the DVDs in this shipment, find the probability that it has the following.

(a) a defective disc or a defective case


(b) a good disc or a good case


(c) a good disc and a good case

Find the probability that the sum is as stated when a pair of dice is rolled. (Enter your answers as fractions.)


(a) even and doubles


(b) even or doubles

In how many ways can three letter arrangments be made from the letters in the word: Computer?