A group of 50 internet shoppers were asked how much they spent per year on the Internet. Their responses are shown in Table 9.7. Find an 80% confidence interval for m, the mean amount spent by all internet shoppers, using the equations found in Chapter 9 as well as statistical software.
418
379
77
212
378
363
434
348
245
341
331
356
423
330
247
351
151
220
383
257
307
297
448
391
210
158
310
331
348
124
523
356
210
364
406
331
364
352
299
221
466
150
282
221
432
366
195
96
219
202