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# Confidence interval for mean

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1. For df = 25, determine the value of A that corresponds to each of the following probabilities:

a.P(t > A) = 0.25
b. P( < A) = 0.10
c. P(-A < t < A) = .99

2. Given the following observations in a simple random sample from a population that is approximately normally distributed, construct and interpret the 90% and 95% confidence intervals for the mea: 67 79 71 98 74 70 59 102 92 96

https://brainmass.com/statistics/confidence-interval/calculations-with-confidence-interval-mean-218490

#### Solution Preview

Statistics
For df = 25, determine the value of A that corresponds to each of the following probabilities:

a. P(t > A) = 0.25
We have P(t >0.684)=0.25 Thus A =0.684

b. P( t< A) = 0.10
We have P(t<-1.316)=0.10 Thus A =-1.316

c. P(-A < t < A) = .99

We have P(-2.787<t<2.787=0.99 Thus A = 2.787

2. Given the following observations in a ...

#### Solution Summary

S=The solution provides step by step method for the calculation of confidence interval for mean . Formula for the calculation and Interpretations of the results are also included.

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