1. The problem is to find the value of $A$ given $z = 0.28$. 2. Usually, in statistics, $z$ represents the z-score, which is calculated by the formula: $$z = \frac{X - \mu}{\sigma}$$ where $X$ is the value, $\mu$ is the mean, and $\sigma$ is the standard deviation. 3. To find $A$, we need more context or a formula relating $A$ and $z$. Since the problem only gives $z = 0.28$, we cannot directly find $A$ without additional information. 4. If $A$ is the cumulative probability corresponding to $z = 0.28$ in the standard normal distribution, then $A = P(Z \leq 0.28)$. 5. Using standard normal distribution tables or a calculator, $A \approx 0.6103$. 6. Therefore, if $A$ is the cumulative probability for $z=0.28$, then: $$A \approx 0.6103$$