An agricultural researcher reasons as follows:A heavy application of potassium fertilizer to grasslands in the spring seems to cause lush early growth but depletes the potassium before the growing season ends.So spreading the same amount of potassium over the growing season might increase yields.He therefore compares two treatments:100 pounds per acre of potassium in the spring (Treatment 1) and 50, 25, and 25 pounds per acre applied in the spring, early summer, and late summer (Treatment 2).The experiment is continued over several years because growing conditions may vary from year to year.

The table below gives the yields, in pounds of dry matter per acre.It is known from long experience that yields vary roughly normally.(Data from R. R. Robinson, C. L. Rhykerd, and C. F. Gross, "Potassium uptake by orchardgrass as affected by time, frequency, and rate of potassium fertilization."Agronomy Journal,54(1962) 351-353.)

Treatment

Year 1

Year 2

Year 3

Year 4

Year 5

1

3902

4281

5135

5350

5746

2

3970

4271

5440

5490

6028

These data are available in the Final Links folder at the bottom of the Week 8 folder on Bb.

1. Do the data give good evidence that Treatment 2 leads to higher average yields?Do test of significance to test the claim using alpha = .05.Please note that the observations arepairedby years.(17 points)

B.Give a 98% confidence interval for the mean increase in yield due to spreading potassium applications over the growing season. (10 points)

1. Attach File