Step-by-step explanation:
In statistics, the empirical rule states that for a normally distributed random variable,
- 68.27% of the data lies within one standard deviation of the mean.
- 95.45% of the data lies within two standard deviations of the mean.
- 99.73% of the data lies within three standard deviations of the mean.
In mathematical notation, as shown in the figure below (for a standard normal distribution), the empirical rule is described as
where the symbol 
(the uppercase greek alphabet phi) is the cumulative density function of the normal distribution, 
is the mean and 
is the standard deviation of the normal distribution defined as 
.
According to the empirical rule stated above, the interval that contains the prices of 99.7% of college textbooks for a normal distribution 
,
Therefore, the price of 99.7% of college textbooks falls inclusively between $77 and $149.
I hope you will like my answer
-4 is greater than - 10 because -4 is closer to 0 than -10 is
Answer:
<em>There's an infinite number of possible answers because there might be any multiplication of 3 for boys and any multiplication of 2 for girls. So, for example:</em>
<em>There might be 3 boys and 2 girls.</em>
<em>There might be 6 boys and 4 girls.</em>
<em>There might be 9 boys and 6 girls.</em>
<em>There might be 12 boys and 8 girls.</em>
<em>etc...</em>
<em>In each case the ratio stays the same - 3 : 2.</em>
<em>Of course there probably can't be more than a few dozens of people in one class, but theoretically we can raise the numbers up to infinite.</em>
Step-by-step explanation:<em>hope this help.</em>
