Question

For this worksheet, each problem gives you a situation that you want to analyze. For each situation, do the following: a) Determine the population(s) and parameter(s) being discussed. b) Determine which tool will help us find what we need (one sample z test, one sample t test, two sample t test, one sample z interval, two sample t interval, two sample t interval) c) Check if the conditions for this tool hold. d) Whether or not the conditions hold, use the tool you chose in part (b). Use C=95% for all confidence intervals and a = 5% for all significance tests. ** Be sure that all methods end with a sentence describing the results. **

Answer 1

Soli- (3) Given that, Grade Betore Grade After 82 (a) population & student of associated math class parameter :- population mean difference bin the grades on Certain math exam before Students & After they take the associated- math class.. (6) One Sample t test (since population Sd of difference is unknown so we use t-distribution) Betove didference Aften (C) 82 -28 54 76 73 23 42

NORMAL -95% CI .. Ditd exence = Grade befose - Grade after. 77 -T-I-TT + -_ ------ ī7-1! +- L -|--|-- TTTT - 125 -100 -75 -50 -25 0 a 5 so

from the above the above probability plot, we see that diff. follows normal distributio, Hence, assumption of nomality holds. (d) one Sample ti Sample size N =5 Sample mean = Exi 4 -2% (-5))+(-2)+(-26) +4. = 120 Mean - - 24 {bi-xe std. deviation = - t (4-6-24) 5-1 13865 -> 1546 - 19.6596 S = 19.66

SE = 5/5 = 19.66 15 = 19.66 с 2.2361 SE = 8.79 interval a t contidence I 19.66 = -24 +1.96 X – -) -24 1.96 x 8.79 - - 24 7 17.23 -> (-41.2, -6.8) :: 95% CI = (-41.2.-6.6) Since, the Contidence interval of difference not Contains Zero. So we are not contident that a grade of scores of Students does improve of joining associated math class.