(20 pts) Vitamins supplements are seen as no guard against diseases according to
ID: 3314078 • Letter: #
Question
(20 pts) Vitamins supplements are seen as no guard against diseases according to one medical study. Suppose 28,000 men on varying vitamins schedules, ages fifty and up and long-tem smokers, were monitored for eight years with the following result 4. Death from Cancer or Stroke 300 300 260260 Lived 6700 6740 6740 6700 Totals 7000 7000 7000 Carotene Vitamins Placebo Assuming valid random samples, test at.01 whether differences can be attributed to chance fluctuation or, 7000 28000 Took Vit. A Took Beta Took Both Took indeed, to actual differences among the three groups.Explanation / Answer
Given table data is as below MATRIX col1 col2 col3 col4 TOTALS row 1 300 300 260 260 1120 row 2 6700 6700 6740 6740 26880 TOTALS 7000 7000 7000 7000 N = 28000 ------------------------------------------------------------------ calculation formula for E table matrix E-TABLE col1 col2 col3 col4 row 1 row1*col1/N row1*col2/N row1*col3/N row1*col4/N row 2 row2*col1/N row2*col2/N row2*col3/N row2*col4/N ------------------------------------------------------------------ expected frequecies calculated by applying E - table matrix formulae E-TABLE col1 col2 col3 col4 row 1 280 280 280 280 row 2 6720 6720 6720 6720 ------------------------------------------------------------------ calculate chisquare test statistic using given observed frequencies, calculated expected frequencies from above Oi Ei Oi-Ei (Oi-Ei)^2 (Oi-Ei)^2/Ei 300 280 20 400 1.429 300 280 20 400 1.429 260 280 -20 400 1.429 260 280 -20 400 1.429 6700 6720 -20 400 0.06 6700 6720 -20 400 0.06 6740 6720 20 400 0.06 6740 6720 20 400 0.06 ^2 o = 5.956 ------------------------------------------------------------------ set up null vs alternative as null, Ho: no relation b/w X and Y OR X and Y are independent alternative, H1: exists a relation b/w X and Y OR X and Y are dependent level of significance, = 0.01 from standard normal table, chi square value at right tailed, ^2 /2 =11.345 since our test is right tailed,reject Ho when ^2 o > 11.345 we use test statistic ^2 o = (Oi-Ei)^2/Ei from the table , ^2 o = 5.956 critical value the value of |^2 | at los 0.01 with d.f (r-1)(c-1)= ( 2 -1 ) * ( 4 - 1 ) = 1 * 3 = 3 is 11.345 we got | ^2| =5.956 & | ^2 | =11.345 make decision hence value of | ^2 o | < | ^2 | and here we do not reject Ho ^2 p_value =0.114 ANSWERS --------------- null, Ho: no relation b/w X and Y OR X and Y are independent alternative, H1: exists a relation b/w X and Y OR X and Y are dependent test statistic: 5.956 critical value: 11.345 p-value:0.114 decision: do not reject HoRelated Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.