Question

Anystate Auto Insurance Company took a random sample of 376 insurance claims paid out during a 1-year period. The average claim paid was $1540. Assume σ = $238.

Find a 0.90 confidence interval for the mean claim payment. (Round your answers to two decimal places.)

lower limit	$
upper limit	$

Find a 0.99 confidence interval for the mean claim payment. (Round your answers to two decimal places.)

lower limit	$
upper limit	$

Answer 1

Formula for Confidence Interval for population Mean When Population Standard deviation is known

Sample Mean : : Average claim paid	1540
Population Standard Deviation :	238
Sample Size : n: Number of insurance claims paid	376
Confidence Level :	.90
: 1-0.90	0.1
/2	0.05
	1.6449

0.90 confidence interval for the mean claim payment

0.90 confidence interval for the mean claim payment

Lower Limit $ 1519.81

Upper Limit $ 1560.19

Confidence Level :	0.99
: 1-0.99	0.01
/2	0.005
	2.5758

0.99 confidence interval for the mean claim payment.

0.99 confidence interval for the mean claim payment

Lower Limit : $1508.38

Upper Limit : $1571.62