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suppose that 0.02% of women with negative mammograms will be diagnosed with brea

ID: 3257091 • Letter: S

Question

suppose that 0.02% of women with negative mammograms will be diagnosed with breast cancer within 2 years, whereas 10% of woman with positive mammograms will be diagnosed with breast cancer within two years. suppose that 7% of the general population of women will have a positive mammogram. a. What is the probability of developing breast cancer over the next 2 years among women in the general population? b. Find predictive value positive (PV+) for mammography. c. Find predictive value negative (PV-) for mammography. suppose that 0.02% of women with negative mammograms will be diagnosed with breast cancer within 2 years, whereas 10% of woman with positive mammograms will be diagnosed with breast cancer within two years. suppose that 7% of the general population of women will have a positive mammogram. a. What is the probability of developing breast cancer over the next 2 years among women in the general population? b. Find predictive value positive (PV+) for mammography. c. Find predictive value negative (PV-) for mammography. a. What is the probability of developing breast cancer over the next 2 years among women in the general population? b. Find predictive value positive (PV+) for mammography. c. Find predictive value negative (PV-) for mammography.

Explanation / Answer

a.  probability of developing breast cancer over the next 2 years among women in the general population?

= P(-ive mmg)*P(-ve mmg will have BC) + P(+ive mmg)*P(+ve mmg will have BC)

= (.02/100)*(1-.07) + (.10)*(.07)

=0.007186 or .07186% is the prob of developing breast cancer over the next 2 years among women in the general population

b. predictive value positive (PV+) for mammography = tp/ tp+fp= (.10*.07)/(.10*.07 + .93*.0002) = 0.974

c. predictive value positive (PV-) for mammography = tn/ tn+fn = (.93*.9998)/(.93*.9998 + .07*.90) = 0.937