{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

Assignment 3

C question 4 project management and random variables

Info iconThis preview shows pages 3–5. Sign up to view the full content.

View Full Document Right Arrow Icon
c) Question 4 – Project Management and Random Variables
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
a) Mean = 145 Variance = 36 Standard Deviation = 6 b) i) Pr ( Z > 3.33) = 0.9996 1-0.9996 = 0.0004 or 0.04% ii) Pr ( Z > -0.67) = 0.2514 or 25% iii) Pr ( -0.67 < Z < 3.33) = 0.7482 or 75% iv) Pr ( Z > ? ) = 0.05 1-0.05 = 0.9500 == z = 1.645 X = 145 + 1.645*6 = 154.87 or 155 minutes Question 5 – Sampling Distribution of Proportions a) The general shape of the sampling distribution of the sample proportion of customers who are satisfied is approximately normal. We can assume that because X is a binomial distribution and we can use a normal distribution to approximate it. Mean () = p b) Pr ( Z < -2.45) = 0.0071 or 0.71% c) Pr ( Z < -3.46) = 0.0003 or 0.03% d) The bookstore’s claim is most likely false because the probability of having less than 45% satisfied customers was extremely low, 0.71%, which means that the bookstore’s true proportion of 50% is wrong. Question 6 – Sampling Distribution of Means
Background image of page 4
a) Mean = 604.02 St. Dev = 64.05 b) The general shape of the sampling distribution of the sample mean is approximately normal. The mean of the sample mean is 604.02. The standard deviation of the sample mean is 9.77. c) Pr ( Z < -0.41) = 0.3409 or 34% d) Mean = 633.23 St. Dev = 103.29 The general shape of the sampling distribution of the sample mean is approximately normal. The mean of the sample mean is 633.23. The standard deviation of the sample mean is 9.99. e) Pr ( Z > -2.09) = 0.0183 1-0.0183 = 0.9817 or 98%
Background image of page 5
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

Page3 / 5

c Question 4 Project Management and Random Variables a Mean...

This preview shows document pages 3 - 5. Sign up to view the full document.

View Full Document Right Arrow Icon bookmark
Ask a homework question - tutors are online