Answer:
At most 15 students scored less than 60 or more than 80.
Step-by-step explanation:
Chebyshev's Theorem states that:
At least 75% of the measures are within 2 standard deviations of the mean.
At least 89% of the measures are within 3 standard deviations of the mean.
In this problem, we have that:
Mean = 70
Standard deviation = 5
Use Chebyshev's theorem to determine the number of students who scored less than 60 or more than 80.
60 = 70 - 2*5
So 60 is two standard deviations below the mean
80 = 70 + 2*5
So 80 is two standard deviations above the mean.
By the Chebyshev's theorem, at least 75% of the students scored between 60 and 80. So at most 25% scored less than 60 or more than 80.
0.25*60 = 15
At most 15 students scored less than 60 or more than 80.
