11. In a sample of crankshaft bearings, we find that 80% satisfy the specifications and 20% do not. Construct a 95% confidence interval for the population proportion of bearings that satisfy the specifications.12. A researcher wants to construct a 96% confidence interval for the population proportion with margin of error no more than i4%. What size sample should she use? 13. In his 1379 experiment, A. Michelson measured the velocity of light in air 100 times. The mean of his sample data was 299,852.4 kmfsec with standard deviation of 79.01 km/'sec. Find a 95% condence interval for the true mean [true value of the speed of light). Today we know that the true value is 299.7345 km/sec, so what can you say about the accuracy of Michelson's measurements