Answer:
The confidence interval is (9.842, 10.158)
Or,
CI = 10 ± 0.158
Explanation:
Sample Mean = M = 10
Standard Deviation = S = 1.9
Sample Size = 782
we need 98% significance
for this, we get the z score of 2.326
Hence we find the upper and lower limits of the confidence interval,
Now, z(S)/√n = (2.326)(1.9)/√(782)
= 0.158
Then,
Upper limit = M + z(S)/√n
Upper limit = 10 + 0.158
Upper limit = 10.158
Lower limit = M - z(S)/√n
Lower limit = 10 - 0.158
Lower limit = 9.842
Hence the confidence interval is (9.842, 10.158)