We will use the empirical rule. For a standard normal distribution the mean is equal to 0 and the standard deviation is equal to 1. Then, between 3 standard deviations below the mean, we have 2.35% + 13.5% + 34% = 49.85% of data, and 1 standard deviation above the mean we have 34% of data. Therefore, the percentage of data that are between 3 standard deviations below the mean and 1 standard deviation above the mean is 49.85%+34% = 83.85%.
In the early months of some year one site added 0.4 million new accounts every day, At this rate , how many days would be needed to add 24 million new accounts?
The volume of the second prism is 576 cubic centimeters. Since both prisms have the same height, I solved for the height using the data given with the first prism (I got 6 centimeters for the height). And then I calculated for the volume of the second prism.
