You need to remember your exponent rules. I don’t know any easier way to do it. These are all the ones I can remember right now
Answer:
1
Step-by-step explanation:
Answer:
Rachel
Step-by-step explanation:
We need to measure how far (towards the left) are the students from the mean in<em> “standard deviations units”</em>.
That is to say, if t is the time the student ran the mile and s is the standard deviation of the class, we must find an x such that
mean - x*s = t
For Rachel we have
11 - x*3 = 8, so x = 1.
Rachel is <em>1 standard deviation far (to the left) from the mean</em> of her class
For Kenji we have
9 - x*2 = 8.5, so x = 0.25
Kenji is <em>0.25 standard deviations far (to the left) from the mean</em> of his class
For Nedda we have
7 - x*4 = 8, so x = 0.25
Nedda is also 0.25 standard deviations far (to the left) from the mean of his class.
As Rachel is the farthest from the mean of her class in term of standard deviations, Rachel is the fastest runner with respect to her class.
