Refer to the data in Exercise 11-14 on the microstructure of zirconia. Find a 95% confidence interval on each of the following:

(a) Slope

(b) Intercept

(c) Mean length when x = 1500

(d) Find a 95% prediction interval on length when x = 1500. Explain why this interval is wider than the interval in part (c).

Transcribed Image Text:

Strength y (psi) Observation Age x (weeks) Number 1 2158.70 15.50 23.75 2 1678.15 3 2316.00 8.00 4 2061.30 17.00 5.00 5 2207.50 19.00 1708.30 1784.70 24.00 2575.00 2.50 7.50 2357.90 10 2277.70 11.00 11 2165.20 13.00 2399.55 3.75 12 13 1779.80 25.00 14 2336.75 9.75 1765.30 15 22.00 16 2053.50 18.00 2414.40 6.00 17 2200.50 12.50 18 19 2654.20 2.00 1753.70 21.50 20