Question

With a capacity of 6,300 people, Royal Caribbean’s Oasis of the Seas is the world’s largest cruise ship. The average beer consumption over 35 randomly selected seven-day cruises on the ship was 81,740 bottles. From historical data you know that the population standard deviation of beer consumption is 4,590 bottles. Royal Caribbean would like to estimate the average beer consumption to plan its beer inventory levels on future cruises. (The ship certainly doesn’t want to run out of beer in the middle of the ocean!)
A. Construct a 95% confidence interval to estimate the average beer consumption per cruise.
B. Verify this interval using excel.
C. What assumptions need to be made about this population?

Answer 1

Step-by-step explanation:

Mean = 81740

Standard deviation = 4590

Sample size = 15

Alpha level = 1-0.95 = 0.05

Df = 15-1 = 14

Critical value:

alpha/2 = 0.05/2 = 0.05

t0.025

t critical value = 2.145

Margin of error ME

2.145 x 4590/√15

2.145 x 4590/3.873

ME = 2542.09

Confidence interval

Lower CI = mean - ME

= 81740-2542.09

= 79197.91

Upper CI = mean + ME

= 81740+2542.09

= 84282.09

[ 79197.91, 84282.09]

B.

Using excel, exact answer for CI

Lower limit = 79198.142724212173

Upper limit = 84281.8572757827

C.

The assumptions to be made from the population are that

1. Samples are random

2. These samples are gotten from an approximately normal distribution