Question

7.3.13 Question Help Twelve different video games showing substance use were observed and the duration of times of game play in seconds) are listed below. The design of the study justifies the assumption that the sample can be treated as a simple random sample. Use the sample date to construct a 95% confidence interval estimate of the standard deviation of the duration times of game play. Assume that this sample was obtained from a population with a normal distribution 3.975 4.935 4,452 4,178 4.391 4.826 4,485 4.752 3,923 3,964 4504 4.050 Click the icon to view the table of CH Square crtical values The confidence interval estimate is *** (Round to one decimal place as needed.)

Answer 1

The solution is done showing all steps with calculations and required explanations. For your better understanding, a chi square table is also attached. Hope you can understand and appreciate the work.

Sample size = n = 12 Sample Mean =ñ= ħ Exis xi's are observations == [3975+4826+...+4604 = 4377.75 Sample Standard Deviations s = $(i-1)* [ite [(3975-4377.75)+ +(4604-4377.75 1.755792 = 334.73 confidence Level = 95% X=1-0.95 -0.05 a = 0.025 & 1-4 = 0.975 Now, tapimai 6.025,11 = 21.92 (value vi = = 3.816 alue from table) - 7 , noi 72.975,11 95% confidence Interval for population standard deviation (6) is given (n-1)? Tenis? 8 1-4 ure asi <o< ar noi Oro (12-1) 21.92 x 334.73 <o</C12-1) *334.73 3.816 (Ausway) 237.6 <o<568.3

chi square table :

Chl-Square (X?) Distribution Area to the Right of Critical Value 0.95 0.90 0.10 0.05 Degrees of Freedom 0.99 0.975 0.025 0.01 1 2 3 4 5 0.020 0.115 0.297 0.554 0.872 1.239 1.646 2.088 2558 0.001 0.051 0.216 0.484 0.831 1.237 1.690 2.180 2.700 3.247 3.841 5.991 7.815 9.488 11.071 12.592 14.067 15.507 16.919 18,307 5.024 7.378 9.348 11.143 12.833 14.449 16.013 17.535 19.023 20.483 9 10 11 12 13 14 15 3.816 4.404 5.009 5.629 6.262 19.675 21.026 22.362 23.685 24.996 21.920 23.337 24.736 26.119 27.488 0.004 0.103 0.352 0.711 1.145 1.635 2.167 2.733 3.325 3.940 4.575 5.226 5.892 6.571 7.261 7.962 8.672 9.390 10.117 10.851 11.591 12.338 13.091 13.848 14.611 15.379 16.151 16.928 17.708 18.493 3.053 3.571 4.107 4.660 5.229 5.812 6.408 7.015 7.633 8.260 8.897 9.542 10.196 10.856 11.524 0.016 0.211 0.584 1.064 1.610 2.204 2.833 3.490 4.168 4.865 5.578 6.304 7.042 7.790 8.547 9.312 10.085 10.865 11.651 12.443 13.240 14.042 14.848 15.659 16.473 17.292 18.114 18.939 19.768 20.599 2.706 4.605 6.251 7.779 9.236 10.645 12.017 13.362 14.684 15.987 17.275 18.549 19.812 21.064 22.307 23.542 24.769 25.989 27.204 28.412 29.615 30.813 32.007 33.196 34.382 35.563 36.741 37.916 39.087 40.256 6.635 9.210 11.345 13.277 15.086 16.812 18.475 20.090 21.666 23.209 24.725 26.217 27.688 29.141 30.578 32.000 33.409 34.805 36.191 37.566 38.932 40.289 41.638 42.980 44.314 45.642 46.963 48.278 49 588 50.892 16 17 18 19 20 21 22 23 24 25 6.908 7.564 8.231 8.907 9.591 10.283 10.982 11.689 12.401 13.120 13.844 14.573 15.308 16.047 16.791 26.296 27.587 28.869 30.144 31.410 32.671 33.924 35.172 36.415 37.652 38.885 40.113 41.337 42.557 43.773 28.845 30.191 31.526 32.852 34.170 35.479 36.781 38.076 39.364 40.646 41.923 43.194 44.461 45.722 46.979 26 12.198 12.879 13.565 14.257 14.954 30