Answer:
The sample size is 
Step-by-step explanation:
From the question we are told that
The sample standard deviation is 
The mean difference of the two groups is 
The standard error is 
=> 
Let assume that the confidence level is 95% hence the level of significance is
=> 
So the critical value of 
obtained from the normal distribution table is
Generally the margin of error is mathematically evaluated as
Generally the sample size is mathematically represented as
![n =[ \frac{Z_{\frac{\alpha }{2} * s^2}}{E}]^2](https://tex.z-dn.net/?f=n%20%3D%5B%20%5Cfrac%7BZ_%7B%5Cfrac%7B%5Calpha%20%7D%7B2%7D%20%20%2A%20s%5E2%7D%7D%7BE%7D%5D%5E2)
=> ![n = [\frac{1.96 * 1.5}{0.49} ]^2](https://tex.z-dn.net/?f=n%20%20%3D%20%5B%5Cfrac%7B1.96%20%2A%201.5%7D%7B0.49%7D%20%5D%5E2)
=>
Explanation:
Basically, you can do it in many ways. But just, in my opinion, exactly linear algebra was made for such cases.
the optimal way is to do it with Cramer's rule.
First, find the determinant and then find the determinant x, y, v, u.
Afterward, simply divide the determinant of variables by the usual determinant.
eg. 
and etc.
I think that is the best way to solve it without a hustle of myriad of calculations reducing it to row echelon form and solving with Gaussian elimination.
Need a little bit more information to be able to answer the question
Answer:
12 percent of the students are ill
Step-by-step explanation:
To find the percent, you want to find the fraction 72/600. If you get your calculator adn divide the fraction, you get 0.12 which is 12 percent. Hope this helps!
