To solve this, we use the z test.
The formula:
z = (x – u) / s
where x is sample value = 20, u is the mean = 15, and s is
the standard deviation = 2.5
z = (20 – 15) / 2.5
z = 2
Since we are looking for values greater than 20, this is
right tailed test. We use the standard distribution tables to find for P.
P = 0.0228
Therefore:
number of students = 100 * 0.0228 = 2.28
<span>2 to 3 students will get greater than 20 measurement</span>
Answer:
D
Step-by-step explanation:
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Answer:
5
Step-by-step explanation:
Dividing fractions is the same as multiplying by its reciprocal so you can change the equation to this

And you can simplify by eliminating the fours and multiplying straight across

You can pull out - 7 from the top and 2 from the bottom so you have this

And then you can cancel out to (2-x) to get an answer of