Chapter 1.3, Problem 14E

Refer to Exercise 1.3 and repeat parts (a) and (b) of Exercise 1.13.

1.13 Refer to Exercise 1.2.

1. a Calculate $\bar{y}$ and s for the data given.
2. b Calculate the interval $\bar{y}\pm ks$ for k = 1, 2, and 3. Count the number of measurements that fall within each interval and compare this result with the number that you would expect according to the empirical rule.

1.3 Of great importance to residents of central Florida is the amount of radioactive material present in the soil of reclaimed phosphate mining areas. Measurements of the amount of ²³⁸U in 25 soil samples were as follows (measurements in picocuries per gram):

Construct a relative frequency histogram for these data.