The effect of acid rain upon the yield of crops is of concern in many places. In order to determine baseline yields, a sample of 13 fields was selected, and the yield of barley (g/400m2) was determined. The output from SAS appears below: QUANTILES(DEF=4) EXTREMES
N 13 SUM WGTS 13 100% MAX 392 99% 392 LOW HIGH
MEAN 220.231 SUM 2863 75% Q3 234 95% 392 161 225
STD DEV 58.5721 VAR 3430.69 50% MED 221 90% 330 168 232
SKEW 2.21591 KURT 6.61979 25% Q1 174 10% 163 169 236
USS 671689 CSS 41168.3 0% MIN 161 5% 161 179 239
CV 26.5958 STD MEAN 16.245 1% 161 205 392
A 95% confidence interval for the mean yield is:.
a. 220.2 ± 1.96(58.6)
b. 220.2 ± 1.96(16.2)
c. 220.2 ± 2.18(58.6)
d. 220.2 ± 2.18(16.2)
e. 220.2 ± 2.16(16.2)