Question

Americans spend nearly $7 billion on Halloween costumes and decorations. Sample data showing the amount, in dollars, 16 adults spent on a Halloween costume are as follows. 34 14 64 96 25 31 1 a. What is the estimate of the population mean amount adults spend on a Halloween costume (to 2 decimals)? b. What is the sample standard deviation (to 2 decimals)? c. Provide a 95% confidence interval estimate of the population standard deviation for the amount adults spend on a Halloween costume (to 2 decimals). Use Table 11.1. Sos$ TABLE 11.1 SELECTED VALUES FROM THE CHI-SQUARE DISTRIBUTION TABLE* Area or probability za 352 .484 Degrees Area in Upper Tail of Freedom 99 975 95 .90 .10 .05 .001 .004 2016 2.706 3.841 .020 .051 .103 211 4.605 5.991 1 .115 .216 584 6.251 7.815 .297 .711 1.064 7.779 9.488 .831 1.145 1.610 9.236 11.070 .872 1.237 1.635 2.204 10.645 12.592 1.239 1.690 2.167 2.833 12.017 14.067 1.647 2.180 2.733 3.490 13.362 15.507 2.088 2.700 3.325 4.168 14.684 16.919 2.558 3.247 3.940 4.865 15.987 18.307 3.053 3.816 4.575 5.578 17.275 19.675 3.571 4.404 5.226 6.304 18.549 21.026 4.107 5.009 5.892 7.041 19.812 22.362 4.660 5.629 6.571 7.790 21.064 23.685 5.229 6.262 7.261 8.547 22.307 24.996 5.812 6.908 7.962 9.312 23.542 26.296 6.408 7.564 8.672 10.085 24.769 27.587 7.015 8.231 9.390 10.865 25.989 28.869 7.633 8.907 10.117 11.651 27.204 30.144 8.260 9.591 10.851 12.443 28.412 31.410 8.897 10.283 11.591 13.240 29.615 32.671 9.542 10.982 12.338 14.041 30.813 33.924 10.196 11.689 13.091 14.848 32.007 35.172 10.856 12.401 13.848 15.659 33.196 36.415 11.524 13.120 14.611 16.473 34.382 37.652 12.198 13.844 15.379 17.292 35.563 38.885 12.878 14.573 16.151 18.114 36.741 40.113 13.565 15.308 16.928 18.939 37.916 41.337 14.256 16.047 17.708 19.768 39.087 42.557 14.953 16.791 18.493 20,599 40.256 43.773 22.164 26.509 29.051 51.805 55.758 60 37.485 40.482 43.188 46.459 74.397 79.082 53.540 57.153 60.391 64.278 96.578 101.879 70.065 77.92982.358 118.498 124.342 *Note: A more extensive table is provided as Table 3 of Appendix B. .025 .01 5.024 6.635 7.378 9.210 9.348 11.345 11.143 13.277 12.832 15.086 14.449 16.812 16.013 18.475 17.535 20.090 19.023 21.666 20.483 23.209 21.920 24.725 23.337 26.217 24.736 27.688 26.119 29.141 27.488 30.578 28.845 32.000 30.191 33.409 31.526 34.805 32.852 36.191 34.170 37.566 35.479 38.932 36.781 40.289 38.076 41.638 39.364 42.980 40.646 44.314 41.923 45.642 43.195 46.963 44.461 48.278 45.722 49.588 46.979 50.892 59.342 63.691 83.298 88.379 106.629 112.329 129.561 | 135.807 80 100