Question
Please, I need help working these out. I have a test tomorrow, and these are practice problems. Also, I really don't understand the difference between a Z* and T* scores. The underlined anwser is correct, I just need help working them out!
THANK YOU!!!
3. Suppose we would like to estimate the mean amount of money spent on books by Troy university students in a semester. We have the following information from 10 randomly selected Troy university students: 249 and 8 = 30, Assume that the amount spent on books by Troy university students is normally distributed To compute a 95% confidence for mean, we will use the following critical value : A, t=1.833 B. z= 1.645 C. t=2.262 D. None of the choices are correct 4. Use the following information to find the P-value. Also, use a 0.05 significance level and state the conclusion about the null hypothesis The test statistic in a left-tailed test is z =-2.05 A. 0.0202: reject the null hvpothesis C.0.4798; fail to reject the null hypothesis B. 0.0404; reject the null hypothesis D. 0.0453; fail to reject the null hypothesis 5. Independent sam ples from two different populations yield the following data. 1 757= 64,81 3.9,82 5.2,n1 = 11, n2 = 9. Find the 98% confidence interval for 1-2 A) (6.96, 16.83) B) (6.96,16.44) C) (6.06,16.38) D) None of the above 6. Veterinary researchers at a major university veterinary hospital calculated a 99% confidence interval for the average age of horses admitted for laminitis, a foot disease that leaves the horse severely lame, as 6.3 to 7.4 years. This confidence intervals tells us that A. the margin of error is 0.55 years. C. the confidence coefficient is 99%. B. the critical value z*-2.576 D. All of the above
Explanation / Answer
3.To compute a 95% confidence for mean the critical value is:
T(df=n-1,0.05)
=t(10-1,0.05)
=t(9,0.05)
=+/-2.2621
4.The P value corresponding t o z=-2.05 is: 0.0202.
Since, P value is less than 0.05, reject the null.
6.The margin of error is: (7.4-6.3)/2=0.55
The mean is 6.85
The critical value is: 2.576
The critical value is 99%.