53. Reconsider the data on area of scleral lamina given in Exercise 49.

a. Determine the lower and upper fourths.

b. Calculate the value of the fourth spread.

c. If the two largest sample values, 4.33 and 4.52, had instead been 5.33 and 5.52, how would this affect fs

? Explain.

d. By how much could the observation 2.34 be increased without affecting fs? Explain.

e. If an 18th observation, x18
4.60, is added to the sample, what is fs?