Manuals/calci/CONFIDENCE

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CONFIDENCE(a,sd,s)


  • is alpha value which is indicating the significance level.
  • is the standard deviation.
  • Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle s} is the size of the sample.


Description

  • This function gives value of the confidence intervals.
  • Confidence intervals are calculated based on the standard error of a measurement.
  • It is measures the probability that a population parameter will fall between lower bound and upper bound of the values.
  • There are four steps to constructing a confidence interval.
   1. Identify a sample statistic.
   2. Select a confidence level. 
   3. Find the margin of error.
   4. Specify the confidence interval. 
  • Normally once standard error value is calculated, the confidence interval is determined by multiplying the standard error by a constant that reflects the level of significance desired, based on the normal distribution.
  • In Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle CONFIDENCE(a,sd,s)} , Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle a} is the alpha value which is indicating the significance level used to find the value of the confidence level.
  • It equals Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle 100*(1-alpha)%} , or alpha of 0.05 indicates a 95 percent confidence level.
  • This value is Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle \plusmn 1.96} .
  • Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle sd } is the standard deviation of the population for the data range.
  • Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle s } is the size of the sample.
  • Confidence interval is calculated using the following formula:
    Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle Confidence interval = sample statistic + Margin of error}
. 
  • So Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle confidence interval =\bar{x}\plusmn 1.96(\frac{\sigma}{\sqrt {s}})}
  • where Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle \bar{x}} is the sample mean,sigma is the standard deviation.
  • This function will give the result as error when
 1. Any one of the argument is nonnumeric. 
 2.Suppose Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle 0\le alpha\le1 }

 3. value of s is less than 1.
  • Suppose with the population of 10 for the standard deviation 3.2, with the alpha value 0.2 then, CONFIDENCE(0.2,3.2,10) =1.296839.
  • So the Confidence interval value is Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle 10\plusmn 1.296839= approximately[11.29,8.70]} .



CONFIDENCE (alpha, SD, n)

Where alpha is the significance level, SD is the population standard deviation for the data range and N is the sample size.


 This function returns a value that can be use to construct a confidence interval for a population mean.

 


·        CONFIDENCE returns the error value, when any argument is nonnumeric or alpha is less than or equal to 0 or grater than equal to 1.

·        CONFIDENCE returns the error value when SD is less than or equal to 0 or n is less than 1.


CONFIDENCE

Syntax

Remarks

Examples

Description

Column1 Column2 Column3 Column4
Row1 0.05 0.993883
Row2 3
Row3 35
Row4
Row5 0
Row6
Row7

AVEDEV (N1, N2...) Where N1, N 2 ...   are positive integers.

Let’s see an example

CONFIDENCE (alpha, SD, n)

 

i.e. =CONFIDENCE (B2, B3, B4) is 0.9939