Download presentation
Presentation is loading. Please wait.
Published byPer-Arne Løken Modified over 6 years ago
1
South Dakota School of Mines & Technology Estimation Industrial Engineering
2
Estimation Interval Estimates Industrial Engineering
3
Interval Estimates Suppose we wish to determine if the mean gpa for women is higher than it is for men. We know that
4
Interval Estimates It stands to reason that if the mean gpa for women is normally distributed and the mean gpa for men is normally distributed, the random variable D = is normally distributed. Further
5
Interval Estimates Further, if then
6
Interval Estimates ) ( 1 z Z P £ - =
Recall that for a standard normal distribution, za/2 za/2 a/2 1 - a ) ( 1 2 / a z Z P - =
7
Interval Estimates Then,
8
Interval Estimates A 1-a confidence interval is then given by
9
Interval Estimates Suppose a sample of 10 women and 20 men yields a sample mean gpa of 2.92 for women and a sample mean gpa of 2.85 for men. We know from past data that the standard gpa for both women and men is Is there evidence to believe women do better than men at the 90% confidence level?
10
Interval Estimates
11
Interval Estimates Suppose a sample of 10 women and 20 men yields a sample mean gpa of 2.92 for women and a sample mean gpa of 2.85 for men. Further, suppose that we estimate the variance for women at 0.08 and the variance for men at Is there evidence to indicate that women do better academically than men?
12
Interval Estimates It’s straightforward that with variance unknown we, switch to the T distribution with a pooled variance. Then, A 1-a confidence interval is then given by
13
Interval Estimates For our problem then, we have
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.