Answer:
90% confidence interval, (109.47,116.53)
For 95% confidence interval (108.79,117.21)
Step-by-step explanation:
n =50
mean = 113
standard deviation = 15.20
a.) For 90% confidence interval, z=1.645
90% confidence interval is

=(113 - 3.53, 113 + 3.53)
=(109.47,116.53)
b.)For 95% confidence interval, z = 1.96
95% confidence interval is

=(113 - 4.21, 113 + 4.21)
=(108.79,117.21)