This worksheet allows you to explore the concept of probability as area under the standard normal distribution curve. Move the points z_a and z_b along the horizontal axis to compute the probability P(z_a < z < z_b).

Small newborn seal pups have a lower chance of survival than larger newborn pups.  Suppose the length of newborn seal pups follow a Normal distribution with a mean of 29.5 inches and a standard deviation of 1.2 inches.[br][br][br]

What is the probability that a randomly selected newborn seal pup is shorter than 32.0 inches? [br][br]Step 1: Find z-score associated with 32.0 inches.[br]Step 2: Move sliders so that area shaded corresponds to z-score area we are interested in.[br]Step 3: Find probability![br][br]

Now, what is the probability that a randomly selected newborn seal pup is [b][u]more[/u][/b] than 32.0 inches? Follow the same steps as in Question 1.[br][br][br][br]

Find the probability that a randomly selected pup will be [u][b]between 27 and 31 inches.[/b][/u] As usual, follow the same steps as the questions above. This time, you will need to move both sliders so that the area shaded represents the interval that we are interested in![br][br][br][br][br][br][br]