Please use the R code, and provide the R code

9. The prevalence of a disease is known to be 0.15. The sensitivity of a test for the disease is 0.98; the specificity is 0.85. a. Calculate the predictive value positive. i. 0.963 ii. 0.914 iii. 0.775 iv. 0.421 b. Calculate the predictive value negative. i. 0.996 ii. 0.953 iii. 0.914 iv. 0.869