The CONFIDENCE function returns a value for creating a statistical confidence interval for a sample from a population with a known standard deviation. All arguments are number values.
CONFIDENCE(alpha, stdev, sample-size)
alpha: The probability that the true population value lies outside the interval. alpha must be greater than 0 and less than 1. Subtracting the confidence interval from 1 yields the alpha.
stdev: The standard deviation of the population. stdev must be greater than 0.
sample-size: The size of the sample. sample-size must be greater than 0.
Notes
The confidence estimate assumes that values in the sample are normally distributed.
Examples |
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=CONFIDENCE(0.05, 1, 10) returns 0.619795032304561. If the mean of the sample values is 100, then with 95% confidence the population mean falls in the range 99.38–100.62. =CONFIDENCE(0.1, 1, 10) returns 0.520148387875558. If the mean of the sample values is 100, then with 90% confidence the population mean falls in the range 99.48–100.52. =CONFIDENCE(0.05, 1, 20) returns 0.438261270288291. =CONFIDENCE(0.05, 1, 30) returns 0.357838828743431. =CONFIDENCE(0.05 ,1, 40) returns 0.309897516152281. |