Elena wants to estimate what proportion of computers produced at a factory have a certain defect. A random sample of 200 computers shows that 12 computers have the defect. She is willing to assume independence between computers in the sample. Based on this sample, which of the following is a 95% confdence interval for the proportion of computers that have the defect?
a. 0.06± 2√(frac 0.06*0.94)/200
b. 12± 2√(frac 12+188)/200
c. 12± 3√(frac 12*188)/200
d. 0.06± 3√(frac 0.06+0.94)/200
