In your question where ask to find the Standard Normal Distribution of the following:
give probabilities for 0<Z<infinity.
For these ranges, you can read directly, for example,
P(Z<1.96)=0.975.
So for #1, you read directly on the line 1.3 and column 0.03.
For #2, we note that the distribution is symmetrical about Z=0, so
P(Z<-2.33) is the same as P(Z>2.33)
which again is the same as
1-P(Z<2.33) because we know that the area under a probability distribution function adds up to 1.
For the remaining questions, work is similar to #2.
The increase of volume = volume of the cube = 1 cubic foot = 1728 cu ins Area of the base = 12 sq ft = 12 * 144 = 1728 sq ins The height of increase = 1728 / 1728 = 1 inch Answer