Answer
a. $75\%$
b. $56\%$
Work Step by Step
Chebyshev’s theorem The proportion of values from a data set that will fall within k
standard deviations of the mean will be at least $1-1/k^2$, where k is a number greater
than 1 (k is not necessarily an integer).
The distribution has a mean of 80 and a standard deviation of 10.
a. At least what percentage of values will fall between
60 and 100? k=2, $1-1/4=0.75$ or $75\%$
b. At least what percentage of values will fall between
65 and 95? k=1.5 $1-1/1.5^2=0.56$ or $56\%$