The answer would be 93% because first we need to do the reverse of how to find the mean... 80 * 4 = 320 and so we just have to subtract the grades from 320... 320 - 79 - 66 - 82 = 93... Thus Jordan's grade was 93

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A study was conducted to determine whether magnets were effective in treating pain. The values represent measurements of pain us

gregori [183]

Answer and Step-by-step explanation: The null and alternative hypothesis for this test are:

$H_{0}: s_{1}^{2} = s_{2}^{2}$

$H_{a}: s_{1}^{2} > s_{2}^{2}$

To test it, use F-test statistics and compare variances of each treatment.

Calculate F-value:

$F=\frac{s^{2}_{1}}{s^{2}_{2}}$

$F=\frac{1.26^{2}}{0.93^{2}}$

$F=\frac{1.5876}{0.8649}$

F = 1.8356

The <u>critical value of F</u> is given by a F-distribution table with:

degree of freedom (row): 20 - 1 = 19

degree of freedom (column): 20 - 1 = 19

And a significance level: α = 0.05

$F_{critical}$ = 2.2341

Comparing both values of F:

1.856 < 2.2341

i.e. F-value calculated is less than F-value of the table.

Therefore, failed to reject $H_{0}$ , meaning there is <u>no sufficient data to support the claim</u> that sham treatment have pain reductions which vary more than for those using magnets treatment.