How to use the CONFIDENCE.NORM function
What is the CONFIDENCE.NORM function?
The CONFIDENCE.NORM function calculates the confidence interval for a population mean.
What is a confidence interval?
A confidence interval provides a range of plausible values for an unknown population parameter like a mean, based on a sample estimate and how much variability exists around that estimate. It is indicating the reliability of the estimate at a specified confidence level.
What is a population mean?
A population mean commonly represented by the Greek letter mμ is the arithmetic average value in a statistical population. It is estimated using the sample mean taken from a representative random sample of the entire population.
What is the variability?
Variability refers to the dispersion or spread of values in a data set and their tendency to deviate from the central mean value. It is quantified by statistical measures like variance, standard deviation, and interquartile range.
What is the arithmetic average value in a statistical population?
The arithmetic average value in a statistical population is the population mean, commonly represented by the Greek letter mu. It is equal to the sum of all the individual values divided by the total number of elements in the full population.
What is the difference between the CONFIDENCE.T function and the CONFIDENCE.NORM function?
The CONFIDENCE.NORM function calculates the confidence interval for a population mean whereas the CONFIDENCE.T function calculates the confidence range for a population mean using a Student's t distribution.
CONFIDENCE.NORM(alpha,standard_dev,size)
CONFIDENCE.T(alpha,standard_dev,size)
CONFIDENCE.NORM Function Syntax
CONFIDENCE.NORM(alpha,standard_dev,size)
CONFIDENCE.NORM Function Arguments
| alpha | Required. The significance level. |
| standard_dev | Required. The standard deviation. |
| size | Required. The number of samples. |
What is the significance level?
The significance level, denoted α (alpha) , is the probability of mistakenly rejecting the null hypothesis when it is in fact true. It is providing a threshold used to judge whether sample evidence is sufficient to indicate a real effect or relationship.
What is standard deviation?
Standard deviation measures the amount of variation or dispersion of values in a dataset relative to the mean. It is calculated as the square root of the variance by taking
- each data point's deviation from the mean
- squaring it
- averaging the squares
- finally square rooting the result
CONFIDENCE.NORM function example
Formula in cell C7:
CONFIDENCE.NORM function not working
The CONFIDENCE.NORM function returns:
- #VALUE! error value if any argument is non-numeric.
- #NUM! error value if
- alpha <= 0 (zero) or alpha >= 1.
- standard_dev <= 0.
- size < 1.
CONFIDENCE.NORM function truncates size numbers to integers.
Functions in 'Statistical' category
The CONFIDENCE.NORM function is one of many functions in the 'Statistical' category.
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