A.) Let X be the random variablebatting average in the 1940's.

Then X ~ Normal(mean = 0.260, sd = 0.07).

Calculate Pr(X > 0.4000). Multiply the answer by 100 to get %.

B.) Let Y be the random variablecontemporary batting average.

Then Y ~ Normal(mean = 0.260, sd = 0.05).

Calculate Pr(Y > 0.4000). Multiply the answer by 100 to get %.

Without knowinghowyou've been taught to calculate for normal distributions (tables, technology such as TI-84, TI-89, statistics software, on-line probability calculators, numerical integration of the pdf etc.) it's impossible to say much more without wasting time .......