Respuesta :
Answer:
1.  χ² =  15.3902
2. The p value is :_____.a. less than .005
3. Â Conclusion
a. health insurance coverage is not independent of the size of the company
4. The percentages of employees
Small %= Â 33/50= 0.66
Medium %= 68/75 = 0.91
Large %= 88/100= 0.88
Step-by-step explanation:
1) We set up our null and alternative hypothesis as
H0: the employee health insurance coverage is independent of the size of the company
against the claim
Ha: the employee health insurance coverage is not independent of the size of the company
2) the significance level alpha is set at 0.05
3) the test statistic under H0 is
χ²= ∑ (O - E)²/ E where O is the observed and E is the expected frequency
which has an approximate chi square distribution with ( 3-1) (2-1)= Â 2 d.f
4) Computations:
Under H0 , the observed frequencies are :
Observed    Expected E     (O-E)     (O-E)²       (O-E)²/E
33 Â Â Â Â Â Â Â Â Â 42 Â Â Â Â Â Â Â Â Â Â Â -9 Â Â Â Â Â Â Â 81 Â Â Â Â Â Â Â Â Â Â 1.928 Â
68 Â Â Â Â Â Â Â Â Â 63 Â Â Â Â Â Â Â Â Â Â Â Â 5 Â Â Â Â Â Â Â 25 Â Â Â Â Â Â Â Â Â 0.3968
88 Â Â Â Â Â Â Â Â Â 84 Â Â Â Â Â Â Â Â Â Â Â Â 4 Â Â Â Â Â Â Â 16 Â Â Â Â Â Â Â Â Â 0.1904
17 Â Â Â Â Â Â Â Â Â Â 8 Â Â Â Â Â Â Â Â Â Â Â Â Â 9 Â Â Â Â Â Â Â 81 Â Â Â Â Â Â Â Â Â 10.125
7 Â Â Â Â Â Â Â Â Â Â 12 Â Â Â Â Â Â Â Â Â Â Â Â Â -5 Â Â Â Â Â Â 21 Â Â Â Â Â Â Â Â Â Â 1.75
12 Â Â Â Â Â Â Â Â Â Â 16 Â Â Â Â Â Â Â Â Â Â Â Â -4 Â Â Â Â Â Â Â 16 Â Â Â Â Â Â Â Â Â Â 1 Â Â Â Â Â Â Â
                                             15.3902  Â
Expected Values are calculated using the formula :
Row Total * Column Total / sample size
E1= (33+17) (33+ 68+88)/ 50+75+100= 42
E4= (33+17) (17+ 7+ 12)/ 50+75+100=8
E2= (68+7) (33+ 68+88)/ 50+75+100= 63
E5= (68+7) Â (17+ 7+ 12)/ 50+75+100= 12
E3= (88+12) (33+ 68+88)/ 50+75+100= 84
E6= (88+12) Â (17+ 7+ 12)/ 50+75+100= 16
5) The critical region is χ² ≥ χ² (0.05)2 = 5.99
6) Conclusion:
The calculated χ² =  15.3902   falls in the critical region χ² ≥  5.99  so we reject the null hypothesis that the employee health insurance coverage is NOT independent of the size of the company.
2. The p value is :_____.
a. less than .005
The p-value is .000385.
3. Â Conclusion
a. health insurance coverage is not independent of the size of the company
4. The percentages of employees
Small %= Â 33/50= 0.66
Medium %= 68/75 = 0.91
Large %= 88/100= 0.88