CALIFORNIA STATE UNIVERSITY,
HAYWARD
STATISTICS DEPARTMENT
Statistics 1000 Elements of Probability and Statistics
MINI-PROJECT 4
Confidence Intervals
- z
Confidence Interval for . Consider
problem 31, page 261: A publisher wants
to estimate the mean length of time adults spend reading newspapers. To do this, the publisher takes a
random sample of 15 people and gets the following results.
11, 9, 8, 10, 10, 9, 7, 11, 11, 7,
6, 9, 10, 8, 10
From
past studies, the publisher assumes is 1.5 minutes. Enter the numbers in C1.
- Construct
a 95% z confidence interval for .
Stat > Basic Statistics > 1-Sample z > C1 > Sigma: 1.5 > OK
- t
Confidence Interval for . Consider
problem 19, page 272: The SAT
score of 12 randomly selected senior high school students are
1424, 1223, 987, 692, 947, 723,
837, 721, 747, 540, 623, 1445
Enter the numbers into C2.
- Calculate
the sample mean and sample standard deviation.
Stat > Basic Statistics > Descriptive Statistics > C1 > OK
- Construct
a 95% t confidence interval for .
Stat > Basic Statistics > 1-Sample t > C2 > OK
- Confidence
Interval for p. Consider
the following problem: Suppose a
class poll is taken to determine the proportion of people who like Roy
Orbison’s music. Of the 20 people
polled 5 say they like his music.
The following data uses 1 = YES and 0 =NO.
1, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0,
1, 0, 0, 1, 0, 0, 1, 0, 1, 0
Enter
the numbers into C3.
- Calculate
a 95% confidence interval for p.
Stat > Basic Statistics > 1 Proportion > C3 > OK