Question

Please answer if you know ALL the parts (a-c) correctly, neatly and in detail.

2. Lower back pain is a common complaint that is hard to treat effectively. Does regular physical therapy help? A randomized experiment assigned patients visiting their doctor for lower back pain to two groups: 142 received an examination and advice from a physical therapist; another 144 received regular physical therapy for up to five weeks. After a year the change in their level of disability (0% to 100%) was assessed by a doctor who did not know which treatment the patients had received. Most changes were negative - that is, the level of disability went down. As usual, some patients did not return after the year had passed. For simplicity, here are data on the patients who did return. Let mean change in level of disability by the population of patients that received an examination and advice from a physical therapist; and u2 = mean change in level of disability by the populations of patients that received regular physical therapy for up to five weeks Group Therapy 101 Advice Mean change Std Dev of change 11.50 -3.75 97 -3.70 11.05 Show all your work and circle your final answers. Suppose the researcher had wished to test the hypotheses Ho : 1 = 2 vs Ha : /1 42 (Use a 0.01). Find the test statistic and P-value, and state your conclusion (both, statistical and in terms of the problem). a) Compute test statistic.

Answer 1

Ans Le changed in devel of disability by the popalation an examinaion t ddvice rom physical theapist- of disability by popl" of patents Tguor physical therapy for upo five weeks mean of patierts thod eaève change thad Teceive leve mean in 150 nil6 -310 he hypathesis to test that Hi Vs test statistic 2 - 3.75 + 3.F0 .50)2 (/1.05) -o. O5 2-5682 o. 031 Cyitical value for a two- tauledl teji Since Ze = 2.58 (onclude that nul hypethesis z O.031 S Zc 2.58 rejected is not Since pO.9751 0.0 P-value Conclude that pull hypothesis is nat vejected. is P o.9751 of both Sample ie. data ane same Conclude tha We mean mean of populatim of paties that Teeeve an exqmination 4 advice rem physica therapist and mean of Ppln regulare physical Sume oF patiens dhat xeceived five weeks therany fer are