Question

for this question, the prof put the critical value as 2.33. Why isnt it 2.457 at df= 49-1 = 48? so df=30 in the table

thanks.

M1Decisan ESTING test, fourth graders should average est stet rsわり I. 2.5 readin domprahensfon euc lv According. to the norms established for a score of 81.4 with a standard deviation of 8.4. If a teacher feels that his 49 students are above average and wants to prove it by giving them this test, what can he conclude at the 1% level of significance if they average 83.9? 2. Acc rding to specifications. the mean bl aw i na time of a a-9 and .10 area in the upper tail, t 1.383 Dis tri but Confidence Intervals 90-95% lay Level of Significance for One-Tailed Test 502 0010 05 Level of Significance for Two-Tailed Test 0.005 | 103 | 6314 12.706 | 31821 63.667 | 636519 31.509 5.841 41.533 213 276 3.7474604 8610 6.B59 144 1.943 24473 3.707 71.415 1895 2.35 2998 3.499 1833 2262 2821 1.796 | 2.201 | 2718 3.106 | 4437 5.408 1.383 1.363 | 1 12 1356 1.782 3.055 2150 2650 3.012 14 1345 1.761 2145 2524 15 13411.75 2132.947 2583 221 16 1.337 1.746 2120 2 17 1.333 1.740 20 2567 2898 18 | 123 1.734 2101 2552 2.878 1.729 203 2539 1,725 206 2528 2845 1211.721 2080 2518 22 1.321 1.717 2074 2508 2819 204 2402 3.745 1316 | 1.708 | LINI 2485 | 2787 2 13151.0 205 2473 1313 1.701 | 204s |1310 | 1.597 | 202 | 2457 | 2750 3.551 3.460 40 1.303 1.671 2000 230

Answer 1

Here, Critical value will be based on Normal distribution and not on T-distribution as population standard deviation is known to us. Also, the sample size is large enough(>30) to assume a Normal distribution.

So,

Critical value of normal distribution at 1% level of significance for upper tailed test is equal to 2.33