91影视

A first-time convicted burglar spends $2.5$ years in prison on average. A random sample of $26$ first-time burglars was chosen, with a mean sentence length of $3$years and a variance of $1.8$years. The variance in the population is $1.5.$

A sample of data from the largest population is usually used for the hypothesis test. This test is used to generate results from sample data based on a hypothesis.

The null hypothesis argues that the two variables have no statistical relationship. The alternative hypothesis suggests that the two variables have a significant relationship.

In the example above, the population and sample data are both normally distributed, and the population standard deviation is provided. As a result, random variable $\stackrel{炉}{X}$will have a normal distribution.

$\stackrel{炉}{X}~N\left(2.5,\frac{1.5}{\sqrt{26}}\right)$