Normal Distribution Using a larger data set than the one given for the preceding exercises, assume that cell phone radiation amounts are normally distributed with a mean of 1.17 W/kg and a standard deviation of 0.29 W/kg.
a. Find the probability that a randomly selected cell phone has a radiation amount that exceeds the U.S. standard of 1.6 W/kg or less.

Normal distribution is a probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean. It is characterized by its bell-shaped curve, defined by its mean and standard deviation. In this context, the cell phone radiation amounts follow a normal distribution with a specified mean and standard deviation.

The mean is the average of a set of values, representing the central point of a data set. The standard deviation measures the amount of variation or dispersion from the mean. In this question, the mean radiation amount is 1.17 W/kg, and the standard deviation of 0.29 W/kg indicates how much individual radiation amounts typically deviate from this average.

Probability calculation involves determining the likelihood of a specific event occurring within a defined set of outcomes. In this case, we need to calculate the probability that a randomly selected cell phone has a radiation amount exceeding 1.6 W/kg. This is typically done using the z-score formula, which standardizes the value in relation to the mean and standard deviation, allowing us to use standard normal distribution tables.