Test 2 Winter 2022 X Time Limit: 2:00:00 Time Left:1:57:35 Hitesh Maheshwari: Attempt 1 Page 1: The average local cell phone call length was reported to be 7.11 minutes. A random 2 sample of 15 phone calls showed an average of 6.66 minutes in length with a -- standard deviation of 1.33 minutes. At &= 0.05, can it be concluded that the average local cell phone call length is less than the population average? Assume that the Page 2: population is approximately normally distributed. 3 4 Perform the following steps of hypotheses testing and draw a conclusion. Tables Page 3: 5 6 1. State the hypothesis. Use these symbols >, > Table F The t Distribution Confidence intervals 80% 90% 95% 98% 99% One tail, a 0.10 0.05 0.025 0.01 0.005 d.f. Two tails, a 0.20 0.10 0.05 0.02 0.01 3.078 6.314 2.70 31.82 3.657 1.886 2.920 4.303 6.965 9.925 1.638 2.353 3.182 4.54 5.841 1.533 2.132 2.776 3.747 4.604 JaUAWN 1.476 2.015 2.571 3.365 4.032 1.440 1.943 2.447 3.143 3.707 1.415 1.895 2.365 2.998 3.490 0 00 N 1.397 1.860 2.306 2.896 3.355 1.383 1.833 2.262 2.821 3.250 10 1.372 1.812 2.228 2.764 3.169 11 1.363 1.796 2.201 2.718 3.106 1.356 1.782 2.179 2.681 3.055 1.350 1.771 2.160 2.650 3.012 1.345 1.761 2.145 2.624 2.977 1.341 1.753 2.131 2.602 2.947 1.337 1.746 2. 120 2.583 2.921 1.333 1.740 2.110 2.567 2.898 1.330 1.734 2. 101 2.552 2.878 1.328 1.729 2.093 2.861 1.325 1.725 2.086 2.528 2.845 1.323 1.721 2.080 2.518 2.831 1.321 1.717 2.074 2.508 2.819 1.319 1.714 2.069 2.500 2.807 1.318 1.711 2.064 2.492 2.797 1.316 1.708 2.060 2.485 2.787 1.315 1.706 2.056 2.479 2.779 1.314 1.703 2.052 2.473 2.771 1.313 1.701 2.048 2.467 2.763 1.311 1.699 2.045 2.462 2.756 1.310 1.697 2.042 2.457 2.750 1.309 1.694 2.037 2.449 2.738 1.307 1.691 2.032 2.441 2.728 1.306 1.688 2.028 2.434 2.719 1.304 1.686 2.024 2.429 2.712 40 1.303 1.684 2.021 2.423 2.704 45 1.301 1.679 2.014 2.412 2.690 50 1.299 1.676 2.009 2.403 2.678 55 1.297 1.673 2.004 2.396 2.668 60 1.296 1.671 2.000 2.390 2.660 65 1.295 1.669 1.997 2.385 2.654 70 1.294 1.667 1.994 2.381 2.648 75 1.293 1.665 1.992 2.377 2.643 80 1.292 1.664 1.990 2.374 2.639 90 1.291 1.662 1.987 2.368 2.632 100 1.290 1.660 1.984 2.364 2.626 500 1.283 1.648 1.965 2.334 2.586 1000 1.282 1.646 1.962 2.330 2.581 2) 00 1.282 .645% 1.960 2.326' 2.576d "This value has been rounded to 1.28 in the textbook. One tail Two tails "This value has been rounded to 1.65 in the textbook. "This value has been rounded to 2.33 in the textbook. Area Area - Area "This value has been rounded to 2.58 in the textbook. 2 Source: Adapted from W. H. Beyer, Handbook of Tables for Probability and Statistics, 2nd ed., CRC Press, Boca Raton, Fla., 1986. Reprinted with permission
