Suppose that 30% of all students who have to buy a text for a particular course want a new copy (the successes!), whereas the other 70% want a used copy. Consider randomly selecting 25 purchasers. a. What are the mean value and standard deviation of the number who want a new copy of the book? b. What is the probability that the number who want new copies is more than two standard deviations away from the mean value?

Mean = 7.5 and standard deviation = 2.29, b) 0.017.fgdgsgdg

Step-by-step explanation:

Since we have given that

Probability of all students who have to buy a text for a particular = 30%

Probability of all students who want a used copy = 70%

Number of purchasers = 25

a. What are the mean value and standard deviation of the number who want a new copy of the book?

Mean = E[x] =

Standard deviation = SD[x] =

b. What is the probability that the number who want new copies is more than two standard deviations away from the mean value?

Hence,a) mean = 7.5 and standard deviation = 2.29, b) 0.017.

a) Mean = 7.5

Standard deviation = 2.29

b) 0.0174            

Step-by-step explanation:

We are given the following information:

We treat student who have to buy a new text as a success.

P(student who have to buy a new copy) = 30% = 0.3

P(student who have to buy a used copy) = 70% = 0.7

Sample size, n = 25

Then the number of adults follows a binomial distribution, where

where n is the total number of observations, x is the number of success, p is the probability of success.

a) mean value and standard deviation of the number who want a new copy

b) P(number who want new copies is more than two standard deviations away from the mean value)

0.0174 is the probability  that the number who want new copies is more than two standard deviations away from the mean value.

maximum area = xy = (16)(32) = 512 ft2

to maximize the area of the garden, the side of the fence parallel to the side of the house should be 32 ft long, and the other two sides should both have length 16 ft.'

source

486in is correct

step-by-step explanation: