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1.Fifteen obese persons were place on a diet for one month. Their weights (in lb

ID: 3132795 • Letter: 1

Question

1.Fifteen obese persons were place on a diet for one month. Their weights (in lbs.) at the beginning and at the end of the month are presented in the following table. Calculate the mean weight loss over a one month period and test the mean decline for statistical significance. Show all hypothesis testing steps. (You can use EXCEL to calculate the summary statistics)

Subject

Initial Weight

Final Weight

1

283

228

2

306

293

3

282

284

4

319

274

5

292

264

6

304

277

7

309

289

8

301

298

9

274

269

10

325

299

11

273

266

12

311

295

13

286

278

14

290

276

15

308

291

Subject

Initial Weight

Final Weight

1

283

228

2

306

293

3

282

284

4

319

274

5

292

264

6

304

277

7

309

289

8

301

298

9

274

269

10

325

299

11

273

266

12

311

295

13

286

278

14

290

276

15

308

291

Explanation / Answer

State the hypotheses: H0: mud=0 (The mean difference is 0)

H1:mud<0 (mean difference is less than 0).

State asumptions: Assume that the paired data collection, independent group assumption, independence assumption, randomization condition and nearly normal condition are reasonably met.

Perform test: Paired t test is applicable in thi sscenario.

n=15 pairs,dbar=-18.80 sd=15.58

SE(dbar)=Sd/sqrtn=15.58/sqrt 15=4.02

t=(dbar-0)/SE(dbar)=-18.80/4.02=-4.68

p value is 0.0000.

Conclusion: The p value is less than alpha=0.05. Therefore, reject null hypothesis to conclude that final weight is less than initial weight.