Question

the mean price is $2.78. Please 4) A sample of 16 overweight people uses a new reducing pill for 6 weeks and has a mean weight loss of 25 lbs. The standard deviation is 8 lbs. a) Find a 95% confidence interval for the mean weight loss. b) If the same information was found using a sample of 50, how would that affect the length of the confidence interval? 5) A study is taken to see if teacher's salaries are lower in New York City than in the rest of the state. In New York State the mean salary for teachers is $54,500 with standard deviation of $9.000. A sample of 36 New York City teachers has a mean salary of $51,500. At the 1 % significance level, is the data sufficient to justify the assertion that New York City teacher's salaries are lower. Justify your answer

Answer 1

n=16, mean= 25, 4) C. T. for mca 9) mean 2ioy20/) 21.08, 28-92) length C- I = 7.84 b) n=s0, gs%-C.I for mea רייב 22.78, 27.22) 25 1.96 * 50) length C-I= 4.44 size inçreaseiCI get's shorter rer.o dengHh of As sample 2e9.0 (s n=36, =SI, S0o Sd = gooo, X:= 54So0, 2=0.01 H: u< 51,S00 Ho: el=S1.S00 Vs test statistic 54S00- SISOO 9000/ J36ora for d=o-01 2table = 2.33 Ztable > Zcal Accept Ho. Decision:- Ho acceptted, here is no Conclusion :- As Sufficient eviden ce to justify New York Feacher salariesare lower.