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For a sample of 140 randomly selected patients the mean amount spent was 86.50 and the standard deviation was 11.45. What is a 95 percent confidence interval for the mean?
Wiki User
∙ 14y ago
sample size, n = 140
standard deviation, s = 11.45
standard error of the mean, SE = s / n^1/2 = 11.45 / 140^1.2 = 0.9677
95% confidence interval => mean +- 1.96SE
95% CI = 86.5 - 1.96*0.9677; 86.5 + 1.96*0.9677
= 84.6; 88.4
Wiki User
∙ 14y ago
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YOU MEET 80 RANDOMLY SELECTED VOTERS AND FIND THAT 54% SUPPORT A CANDIDATE FOR THE LEGISLATURE OF MONAGAS. USING A CONFIDENCE LEVEL OF 95% CALCULATE THE LIMIT OF PERCENTAGE OF VOTERS WHO PREFER THE REFERRED CANDIDATE?
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