g.lemaitre said:it's rare that such a simple problem takes this long. let me provide the example from the book
A normal distribution is a probability distribution that is symmetrical and bell-shaped. It is often used to describe real-world phenomena such as height, weight, and test scores.
The probability of a normal distribution is calculated using the standard normal distribution table, which provides the probabilities for different values of the standard normal variable. This variable is calculated by subtracting the mean from a given value and dividing by the standard deviation.
The 68-95-99.7 rule is a commonly used rule in normal distribution. It states that approximately 68% of data falls within one standard deviation of the mean, 95% falls within two standard deviations, and 99.7% falls within three standard deviations.
A normal distribution is any probability distribution that follows a bell-shaped curve, while a standard normal distribution is a specific normal distribution with a mean of 0 and a standard deviation of 1. The standard normal distribution is often used for calculations and comparisons.
The normal distribution is often used in hypothesis testing to determine the probability of obtaining a certain sample mean from a population. It is also used to calculate critical values and confidence intervals, which are important in determining the significance of a hypothesis test.