Question

Researchers Vogel et al. (JAMA, 2006) reported the following findings about the Study of Tamoxifen and Raloxifene (STAR), a study involving postmenopausal women who were at an increased risk for invasive breast cancer. Of the 10323 women randomly assigned to use tamoxifen daily, 174 developed invasive breast cancer sometime during the next five years, compared to 185 in the group of 10580 who were randomly assigned to use raloxifene daily.Use an appropriate applet to find and report the standardized statistic and theory-based p-value from the data.

Round your answer to 4 decimal places, e.g. 0.0083.
​Find the observed difference in proportion of breast cancer cases between the tamoxifen and raloxifene users.

Use an appropriate applet to find and report the standardized statistic and theory-based p-value from the data.
​Round standardized statistic to 2 decimal places, e.g. 0.83 and p-value to 4 decimal places, e.g. 0.0083.

Answer 1

Researchers Vogel et al. (JAMA, 2006) reported the following findings about the Study of Tamoxifen and Raloxifene (STAR), a study involving postmenopausal women who were at an increased risk for invasive breast cancer. Of the 10323 women randomly assigned to use tamoxifen daily, 174 developed invasive breast cancer sometime during the next five years, compared to 185 in the group of 10580 who were randomly assigned to use raloxifene daily.Use an appropriate applet to find and report the standardized statistic and theory-based p-value from the data.

Round your answer to 4 decimal places, e.g. 0.0083.
​Find the observed difference in proportion of breast cancer cases between the tamoxifen and raloxifene users.

observed difference in proportion = -0.0006

Use an appropriate applet to find and report the standardized statistic and theory-based p-value from the data.
​

standardized statistic z = -0.35

P value = 0. 0.7258

Round standardized statistic to 2 decimal places, e.g. 0.83 and p-value to 4 decimal places, e.g. 0.0083.

Since calculated P=0.7258 which is > 0.05 level of significance, Ho is not rejected. We conclude that there is no significant difference between proportion of breast cancer cases between the tamoxifen and raloxifene users.

Z Test for Differences in Two Proportions
Data
Hypothesized Difference	0
Level of Significance	0.05
Group 1
Number of Items of Interest	174
Sample Size	10323
Group 2
Number of Items of Interest	185
Sample Size	10580
Intermediate Calculations
Group 1 Proportion	0.016855565
Group 2 Proportion	0.017485822
Difference in Two Proportions	-0.000630257
Average Proportion	0.0172
Z Test Statistic	-0.3507
Two-Tail Test
Lower Critical Value	-1.9600
Upper Critical Value	1.9600
p-Value	0.7258
Do not reject the null hypothesis