8.) The scientists are trying to determine the braking strength of a fiber. They took measure 50 specimen and finds the average ( 140 mathrm{psi} ) and variance ( 8 mathrm{psi}^{2} ). They calculated upper and lower confidence values for ( 96 % ) confidence interval of the mean breaking strength. What would be lower and upper confidence level in this case? 9.) A computer chip manufacturer wants to determine percentage of the chips that are defective. The manufacturer does not want the margin of error to be greater than ( 3 % ) when ( 95 % ) confidence interval constructed. a. Assume initial estimate is ( 10 % ) for defective parts. How many samples should, at least, be tested by the manufacturer? b. If there is no initial estimate for percentage of defective parts; then how many samples should, at least, be tested by the manufacturer? 10.) A pair of data ( (X, Y) ) is given below. What is the correlation between ( X ) and ( Y ) ? 11.) For the data below a. if you develop a linear regression model ( y=b_{0}+b_{1}{ }^{*} x ), What would be the equation? b. What will be the predicted value of ( mathrm{y} ) when ( mathrm{X}=1.75 ) ?

8.) The scientists are trying to determine the braking strength of a fiber. They took measure 50 specimen and finds the average 140 psi and variance 8 psi?. They calculated upper and lower confidence values for 96% confidence interval of the mean breaking strength. What would be lower and upper confidence level in this case? 9.) A computer chip manufacturer wants to determine percentage of the chips that are defective. The manufacturer does not want the margin of error to be greater than 3% when 95% confidence interval constructed. a. Assume initial estimate is 10% for defective parts. How many samples should, at least, be tested by the manufacturer? b. If there is no initial estimate for percentage of defective parts; then how many samples should, at least, be tested by the manufacturer? 10.) A pair of data (X,Y) is given below. What is the correlation between X and Y? Y 2 4 3 5 4 3 2 3 3 8 2 5 7 6 11.) For the data below a. if you develop a linear regression model y=bo+b, "X, What would be the equation? X 2 3 1 Y 4 5 3 4 3 2 3 8 2 5 7 6 b. What will be the predicted value of y when x=1.75? c. What are the error estimations for the first three y measurements? X Error Y- 2 ? 3 ? ?