I think that you have forgot to add the choices along with the question. This has made answering difficult, but it is not unanswerable. "A two-way table" is <span>used to summarize two potentially related categorical variables. I hope that this is the answer that you were looking for and it has actually come to your desired help.</span>
If the '7t' is supposed to be '7y', then the answer is below
(4y+8)-(7y-12)=11
distribute the negative into the second parenthesis
4y+8-7y+12=11
combine like terms
-3y+20=11
subtract the 20 from both sides
-3y=-9
divide by -3 on both sides
y=3
if it is supposed to be '7t', I'm not sure if there's enough information
It may help you to consider the standard normal curve. If the mean here is 70%, then 0.5 of the area under this curve. In other words, half the students received a grade > 70%. That would be 100 students.
Note that 84 is 2 std dev above the mean.
Recall the Empirical Rule: 95% of scores lie within 2 std. dev of the mean.
Measuring from the mean, that would be 47.5% above the mean and 47.5% below the mean. The area to the right of the mean is 0.5. Subtract 0.475 from that to obtain the fraction of students who rec'd a grade greater than 2 std dev from the mean: It's 0.025.
Then the # of students who rec'd a grade greater than 84% would be
0.025(200 students) = 5 students.
Answer: (x - 2y) + 3
Step-by-step explanation: The quantity x minus 2y is (x - 2y), then we add 3.
