Answer:
0.9007 is the probability that a student scored below 86 on this exam.
Step-by-step explanation:
We are given the following information in the question:
Mean, μ = 77
Standard Deviation, σ = 7
We are given that the distribution of examination grades is a bell shaped distribution that is a normal distribution.
Formula:

a) P(student scored below 86)
P(x < 86)
Calculation the value from standard normal z table, we have,

0.9007 is the probability that a student scored below 86 on this exam.
The reciprocal of -2/5, expressed as a decimal to the nearest tenth is: -2.5.
<h3>What is the Reciprocal of a Number?</h3>
The reciprocal of a number can be described as the inverse of that number. For example, if a is given as a real number, therefore, the reciprocal of a would be 1/a.
Another example is a/b. The reciprocal of a/b is b/a.
Thus, the reciprocal of -2/5 is -5/2.
Expressing this as a decimal, we would have:
-5/2 = 2.5 (nearest tenth).
Therefore, the reciprocal of -2/5, expressed as a decimal to the nearest tenth is: -2.5.
Learn more about the reciprocal of a number on:
brainly.com/question/20896748
#SPJ1
She will be able to cover 469.875 meters