Scribd
Upload
7 views3 pages

Practice Questions Lecture 38-42

The document contains practice questions for a statistics course, covering topics such as hypothesis testing, confidence intervals, and comparisons of means. It includes specific problems related to sample data and statistical calculations. Additionally, it provides answer keys and conclusions for some of the questions, indicating whether certain hypotheses are rejected or not.

Uploaded by

sheeeerazahmad
Copyright
© © All Rights Reserved
We take content rights seriously. If you suspect this is your content, claim it here.
Available Formats
Download as DOCX, PDF, TXT or read online on Scribd
7 views3 pages

Practice Questions Lecture 38-42

The document contains practice questions for a statistics course, covering topics such as hypothesis testing, confidence intervals, and comparisons of means. It includes specific problems related to sample data and statistical calculations. Additionally, it provides answer keys and conclusions for some of the questions, indicating whether certain hypotheses are rejected or not.

Uploaded by

sheeeerazahmad
Copyright
© © All Rights Reserved
We take content rights seriously. If you suspect this is your content, claim it here.
Available Formats
Download as DOCX, PDF, TXT or read online on Scribd
You are on page 1/ 3

Course STA 301: Statistics and Probability

Practice Questions
Lecture No 38 to 42

Q1: If n=10 and then find the value of .

Q2: If n=5 and then find the value of .

Q3: Write down critical region for the following hypothesis.

Q4: Calculate the pooled proportion for the given data.

Sample I:
Sample II:

Q5: What are paired samples?

Q6: Define two-sample tests.

Q7: Formulate 90% confidence interval for population variance, where n=8.

Q8: Given that X is normally distributed and given the sample values =42, S=5 and n=20.
Find the 98 percent confidence interval for .

Q9: Given that X is normally distributed and given the sample values ,
and n=10. Find the 95 percent confidence interval for .

Q10:

Q11: A sample of 100 electric light bulbs of type I showed a mean lifetime of 1190 hours and a
standard deviation of 90 hours. A sample of 75 bulbs of type II showed a mean of 1230
hours with a standard deviation of 120 hours. Is there a difference between the mean
lifetimes of two types at a significant level of 5%?
Q12: Random samples of 200 bolts manufactured by machine A and 100 bolts manufactured
by machine B showed 19 and 5 defective bolts respectively. Test the hypothesis that
machine B is performing better than machine A. Use a 0.05 level of Significance.

Q13: Calculate

Answer Keys

A1:

A2:

A3: =42.557

A4:

A6:
A8:
A9:

A10:

A11:
Conclusion:

Since the calculated value of = 2.42 is greater than the critical value of = 1.96, so we
reject Or also we conclude that there is a difference between the two types of bulbs.

A12:

Conclusion:
Since the calculated value of z=-1.35 is greater than the critical value of =-1.645, so we don’t
reject Or also we conclude that machine B is not performing better than machine A.

A13: As v1=11 and v2=9 So, F0.05 (11, 9) = 3.10

You might also like