Question

Statistics - Calculate difference in proportions and chi-square values.

Do by hand, not in R or Excel. Show formulas

1) Calculate difference in proportions

2) Calculate chi-square values

Cell phones and cancer

	Cancer	Cancer
Cell phone	Yes	No
Yes	53	102
No	485	693

Answer 1

1) H0: There is no significance difference among the proportion of cell phone users and attack cancer

H1: There is significance difference among the proportion of cell phone users and attack cancer

Let the los be alpha = 5%

From the given data

	Cancer
Cell Phone	Yes	NO	Total
Yes	53	102	155
NO	485	693	1178
Total	538	795	1333

1st sample proportion p1 = 53/155 = 0.341935
2nd sample proportion p2 = 485/1178 = 0.411715

P-value = 0.0960

Z-critical value = +/- 1.96

Here P-value > alpha 0.05 and z value is in z critical values, so we accept H0

Thus we conclude that There is no significance difference among the proportion of cell phone users and attack cancer

2)

H0: There is no significance difference among the proportion of cell phone users and attack cancer

H1: There is significance difference among the proportion of cell phone users and attack cancer

Let the los be alpha = 5%

	Cancer
Cell Phone	Yes	NO	Total
Yes	53	102	155
NO	485	693	1178
Total	538	795	1333

Critical X^2: 3.841456
P-Value: 0.0960

Here P-value > alpha 0.05 and Chisquare value < Chisquare critical value, so we accept H0

Thus we conclude that There is no significance difference among the proportion of cell phone users and attack cancer