Question

PRINT BACK Reserve Problems Chapter 13 Section 2 Problem 2 An article in the American Journal of Emergency Medicine compared the ability to detect acute traumatic aortic injury (ATAI) on cervical x-ray images. The data consisted of 13 cases of ATAI, 19 cases with negative aortography (NAO) and 18 cases with multiple trauma (MT) without aortography. Measurements of the cervical soft-tissue width at the third cervical vertebrae generated the following results. Averages were 8.4, 8.8 and 6.2 mm and standard deviations were 3.1, 2.6 and 2.9 mm for the ATAI, NAO, and MT groups, respectively. Consider an ANOVA for these data. a) Use the sample sizes and group averages to compute the grand mean width and the mean square for treatments. Round your answer to two decimal places (e.g. 9.87). U=I MS Treatments b) Use the sample sizes and standard deviations in the groups to compute the mean square error. Round your answer to two decimal places (e.g. 9.87). MSETO c) Use the results in the previous parts to conduct the ANOVA test and prove that the mean widths do not differ. Calculate the P-value for the test. Source SS (to two decimal places) DF MS (to two decimal places) P (to three decimal places) F (to two decimal places) Treatments Error Total

Answer 1

1 Answer- The Given information is Number of cases AT A 1 0,=13 NAO n=19 3:18 17 → Average , =84 ELET, Ą =9.8 = 6.2 Standard deviations Sq=3.1 S2 =2.6 $3 -2.9 a ) art M: 8 te dai strana la 13+19+1% [ni Fi + +03) Šo (13 (8-4) +19.68.9 +18C62) Ma (7.76 MS medments - Missa = ( 2 or (4 - 1/2 **[, 65,-pi?+ , (T-mo? tn (75-M)] (13 (8.4-7.791-719688-776+19(62- MS. + (69.68] =84-84] 775

☺ > MSTA SSTO df=2 df = ssandfanston = 2 x 34.84 = 69.66 SSE MS Ennon MISE dhe SSE (R; -ā;)? 3 & nos? ans, trastons = 13(3-1) +19(2.37+1% (2.912 you.75 since afgotal 50-1=49 atas 2 df ਗ ५१-१- ५ MSE 3 you. 25 47 8.61 F = MSD MSE Fa 34.84 F2,47 8.61 - 14.05 P-value ip C Sant 34.03) - 1-PC F2, 42 34 85 0.74 is higes s do not differ DF Sounce Treatments 7707 Total 2 (47) 99 SS MS (69.68 34.84 4.05 (0.74 you. 75 8.61 1474.13