Answer:
95% confidence interval for the population mean is 20.255 and 17.945
Step-by-step explanation:
given data
mean = 19.1
standard deviation = 1.5
n = 9
to find out
95% confidence interval for the population mean
solution
we know 95% confidence interval formula i.e.
mean +/- t * standard deviation/ .............1
here t for 9 students 2.31 ( from t table)
so put all value n t standard deviation and mean in equation 1
= mean +/- t * standard deviation/
= 19.1 +/- 2.31 * 1.5/
= 19.1 +/- 2.31 * 1.5/
= 20.255 and 17.945
95% confidence interval for the population mean is 20.255 and 17.945