Question

The relationship between "strength" and "fineness" of cotton fibers was the subject of a study that produced the following data. (Give your answers correct to two decimal places.)

x, Strength	75	78	74	69	80	82	80	86	70	88
y, Fineness	3.8	4	4.5	3.7	4.3	3.8	3.8	4.7	4.8	3.7

(a) Find the 98% confidence interval for the mean measurement of fineness for fibers with a strength of 76.

Upper Limit -

Lower Limit-

(b) Find the 99% prediction interval for an individual measurement of fineness for fibers with a strength of 76.

Upper Limit -

Lower Limit-

Answer 1

Answer Date: 13/04/2019 a) The 98% confidence interval for the mean measurement of fineness for fires with strength of76 is, yusing Excel software, find confidence interval with the help of fo 1) mport the data. 2) Select the MegaStat from Add-Ins option. 3) ect the Regression Analysis from Regression. 4) Select data input. 5) Enter Predictor value from Predictor value form spreadsheet. 6) Click Ok. Predicted values for: Fineness 98% Confidence Interval 98% Prediction Interval StrengthPredictedlower upper lowerupper 4.1304 3.6915 4.5694 2.7558 5.5051 76 From the Excel output, the 98% confidence interval for the mean measurement of fineness for fibres with strength of 76 is 3.69 to 4.57

b) The 99% prediction interval for the mean measurement of fineness for fibres with strength of 76 is, By using Excel software, find prediction interval with the help of following steps: 1) Import the data. 2) Select the MegaStat from Add-Ins option 3) Select the Regression Analysis from Regression 4)Select data input. 5) Enter Predictor value from Predictor value form spreadsheet. 6) Cick Ok. 99% confidence İnterval 99% Prediction Interval Strength Predicted lowerupper lowerupper 4.1304 3.6219 4.6389 2.5380 5.7229 76 From Excel output, the 99% prediction interval for the mean measurement of fineness for fibres with strength of 76 is 2.54 to 5.72