The mean time taken to learn the basics of a software program by all students is 200 minutes with a standard deviation of 20 minutes.
a. Using Chebyshev’s theorem, find at least what percentage of students will learn the basics of this software program in
i. 160 to 240 minutes
ii. 140 to 260 minutes
b. Using Chebyshev’s theorem, find the interval that contains the times taken by at least 75% of all students to learn this software program.