The graph shows a standard normal distribution, where the mean is 0 and the standard deviation is 1. The shaded region is bounded by two z-scores: $z = -0.86$ and $z = 1.26$.

To find the area of the shaded region, we calculate the cumulative area under the standard normal curve between these two z-scores. This is done by using the cumulative distribution function (CDF) for the standard normal distribution.

Steps:

1. Find the cumulative probability corresponding to $z = 1.26$.
2. Find the cumulative probability corresponding to $z = -0.86$.
3. Subtract the cumulative probability of $z = -0.86$ from that of $z = 1.26$ to get the area of the shaded region.

Let's calculate this now.The area of the shaded region between the z-scores $z = -0.86$ and $z = 1.26$ is approximately 0.7013 (rounded to four decimal places).

Would you like further details on this calculation or have any other questions?

Here are some related questions for further exploration:

1. How is the cumulative distribution function (CDF) used in normal distribution calculations?
2. What is the significance of z-scores in statistics?
3. How do you calculate probabilities for standard normal distributions without a table?
4. What are the properties of a standard normal distribution?
5. How can confidence intervals be visualized using normal distribution graphs?

Tip: You can use standard normal tables or statistical software to quickly find areas under the normal curve based on z-scores.