1)A runner's finishing time translated into a z-score of z=2.6

Question

Explain in words whether the runner performed excellently or poorly?

2)Yearly stock returns on India's Sensex Index are well described by a Normal model with a mean of 18.36% and a standard deviation of 14.65%. give the stock return cutoff for the middle 30% of all years.

Answer 1

z-scores mainly range between -3 and 3
z = 2.6 is near the upper end.