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Problem 14.18 A public official believes that the mean household water use is 1,315 liters per day. A study of water usage involved a random sample of twenty five households. The data are given below. Assume that the household water use is normally distributed. 1316 1341 1303 1322 1335 1306 1320 1307 1352 1344 1329 1342 1301 1317 1311 1328 1290 1322 1310 1348 1324 1322 1339 1334 1369 (a) Using these data, is there enough evidence to conclude that the mean household water use is not 1,315 liters per day? Use a = 0.05. (b) Construct a 90% confidence interval for the mean household water use per day