Answer:
It is not possible for Alice to score an average of 75% because what she needs to score in the fifth exam exceeds the maximum possible score.
Step-by-step explanation:
She scored an average 68% in all 4 exams.
This means; (68% + 68% + 68% + 68%)/4
Now, a fifth exam is added and we want to know if her average can now be 75%.
Thus, let the score in the 5th exam be x and we now have;
(68% + 68% + 68% + 68% + x)/5 = 75%
Multiply both sides by 5 to get;
(68% + 68% + 68% + 68% + x) = 375%
272% + x = 375%
x = 375% - 272%
x = 103%
The maximum score is 100% and therefore it is impossible for her to score 103%. Therefore it is not possible for Alice to score an average of 75%
Answer:
The critical value of <em>t</em> at 0.01 level of significance is 2.66.
Step-by-step explanation:
The hypothesis for the two-tailed population mean can be defined as:
<em>H₀</em>: <em>μ </em>= <em>μ₀</em> vs. <em>H₀</em>: <em>μ </em>≠ <em>μ₀</em>
It is provided that the population standard deviation is not known.
Since there is no information about the population standard deviation, we will use a <em>t</em>-test for single mean.
The test statistic is defined as follows:

The information given is:
<em>n</em> = 55
<em>α</em> =<em> </em>0.01
Compute the critical value of <em>t</em> as follows:

*Use a <em>t</em>-table for the value.
If the desired degrees of freedom are not provided consider he next highest degree of freedom.
Thus, the critical value of <em>t</em> at 0.01 level of significance is 2.66.
Answer: is A
Step-by-step explanation:
*115*
do the parentheses in the parentheses first, then the outer parentheses, then the stuff outside the parentheses.
PEMDAS
parentheses...exponents...multiplication/division...Addition/subtraction.