genevieve03
New member
- Joined
- Dec 8, 2011
- Messages
- 1
1.)Kelly wanted to estimate the difference between the percentages of users of automobiles who would never change car brands. She took a sample of 500 users of Toyota (100 of who said they would never switch) and 400 users of Ford(68 of who said they would never switch).
A.) Let p1-p2 represent the two groups that use the above automobiles. What would the point estimate for p1-p2?
B.) Construct a 97% confidence interval for the difference between proportions of all users of the two automobiles who will never switch.
2.) Average scores for a test taken before learning the topic, then the results following:
Before |12|18|25| 9 |14|16|
After |18|24|24|14|19|20|
The problem is: Construct a 95% confidence interval for μd.
At the 1% significance level, can we conclude that the mean scores increase in the after category?
I'd just like to understand how to do these problems better. I have an exam coming up so I need all the practice I can get. Thank you!
A.) Let p1-p2 represent the two groups that use the above automobiles. What would the point estimate for p1-p2?
B.) Construct a 97% confidence interval for the difference between proportions of all users of the two automobiles who will never switch.
2.) Average scores for a test taken before learning the topic, then the results following:
Before |12|18|25| 9 |14|16|
After |18|24|24|14|19|20|
The problem is: Construct a 95% confidence interval for μd.
At the 1% significance level, can we conclude that the mean scores increase in the after category?
I'd just like to understand how to do these problems better. I have an exam coming up so I need all the practice I can get. Thank you!