There are 11 books on a shelf. 5 of these books are new. (a) What is the ratio of new books to used books? (b) What is the ratio
1 answer:
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Answer:
[ 21.79, 33.0 ]
Step-by-step explanation:
Given:
Sample size, n = 7
Sample mean, μ = 27.4
Standard deviation, σ = 5.75
Confidence level is 99%
also, population is normal i.e normally distributed
Thus,
Confidence interval = μ ±
For confidence level of 99%
z-value = 2.58
Therefore,
Lower limit of Confidence interval = μ -
or
Lower limit of Confidence interval = 27.4 -
or
Lower limit of Confidence interval = 21.79
Upper limit of Confidence interval = μ +
or
Upper limit of Confidence interval = 27.4 +
or
Upper limit of Confidence interval = 33.00
Hence, confidence interval = [ 21.79, 33.0 ]