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1'. The president of a large university wishes to estimate the average age of the students presently enrolled,
From past studies, the standard deviation is known to be 2 years. A sample of 50 students is selected, and
themeanisfoundtobe23.2years. Findtheg0%confidenceintervalofthepopulationmean.
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within 6 ounces of the sample mean? The
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standard deviation of the birth weights is known to be 8 ounces.
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A company that installs swimming pools for residential customers sells a pool packageto t8% of the
customers its representatives visit, lf the sales reps visit 180 customers, find the probability of their making
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deviation of
A sample of 20 tuna showed that they swim an average of 8.6 miles per hour with a standard
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A researcher wishes to be 92% confident that her estimate of the true
overseas is within 0.04 of the true proportion. Find the sample size necessary'
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lf 24 irons are selected,
The average lifetime of irons is 9 months. The standard deviation was 3,L months.
find the probability that the mean lifetime is between 8 and 10 months.
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What does the 90% confidence level mean?
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