The mean is and standard deviation is
. Then the variable
.
Use substitution , then the variable
.
The probability can be calculated in the following way:
for X=80, and
. From the diagram
.
Conclusion: if 188 students take the exam, then 188·0.84=157.92 (157) would receive a score above 80
Answer: draw a diagonal line
Step-by-step explanation:
like this:
since it's going up, it's a positive slope
Answer:
0.86
Step-by-step explanation:
The z-score we need to make the comparison is given by
where
= the standard deviation established in the study
n = the sample size
and for the Normal distribution N(0,1) we want to find
<em>P(X > -1.0801) </em>
By using a spreadsheet or the table attached, we find that
P(X > -1.0801) = 0.86
(See picture attached)
