Refer to Exercise 21.

Use the normal approximation to estimate the critical values X2 0.025 and X2 0.975. Using these critical values, can you reject H0 at the

α = 0.05 level?

A sample of size 101 from a normal population has sample standard deviation s = 40. Use Table A.4 to find the exact critical values X2 0.025 and X2 0.975 to test H0: σ = 30 versus H1: σ ≠ 30. Can you reject H0 at the α = 0.05 level?

Exercise 21

A sample of size 101 from a normal population has sample standard deviation s = 40.

Use Table A.4 to find the exact critical values X2 0.025 and X2 0.975 to test H0: σ = 30 versus H1: σ ≠ 30.

Can you reject H0 at the α = 0.05 level?

Table A.4 Critical Values for the x Distribution Area Degrees of Area in Right Tail Freedom 0.995 0.99 0.975 0.95 0.90 0.10 0.05 0.025 0.01 0.005 1 0.000 0.000 0.001 0.004 0.016 2.706 3.841 5.024 6.635 7.879 2 0.010 0.020 0.051 0.103 0.211 4.605 5.991 7.378 9.210 10.597 3 0.072 0.115 0.216 0.352 0.584 6.251 7.815 9.348 11.345 12.838 4 0.207 0.297 0.484 0.711 1.064 7.779 9.488 11.143 13.277 14.860 5 0.412 0.554 0.831 1.145 1.610 9.236 6 0.676 0.872 1.237 1.635 2.204 10.645 7 0.989 1.239 1.690 2.167 8 1.344 1.646 2.180 2.733 9 1.735 2.088 2.700 3.325 10 2.156 2.558 3.247 3.940 11 2.603 3.053 3.816 12 3.074 3.571 4.404 5.226 11.070 12.833 15.086 16.750 12.592 2.833 12.017 14.067 3.490 13.362 15.507 4.168 14.684 16.919 4.865 15.987 18.307 4.575 5.578 17.275 19.675 6.304 18.549 21.026 13 3.565 4.107 5.009 5.892 7.042 19.812 22.362 14.449 16.812 16.013 18.475 20.278 17.535 20.090 21.955 19.023 21.666 23.589 20.483 23.209 25.188 21.920 24.725 26.757 23.337 26.217 28.300 24.736 18.548 27.688 29.819 14 4.075 4.660 15 4.601 5.229 5.629 6.571 6.262 7.790 21.064 23.685 26.119 29.141 31.319 7.261 8.547 22.307 24.996 27.488 30.578 32.801