Question

·Write a Cl Calculator in MATLAB (function name ci_calc.m). Your function should take four input arguments: σ, x,n, p% Confidence Interval Calculator σ (Std Dev) Sample mean Sample size Confidence level 577.4 37.4556 100 90% Numeric input Numeric input Numeric input Numeric input Lower limit of Cl -57.52 Numeric output Upper limit of Cl 132.43 Numeric output

Answer 1

MATLAB Code:

function [lCI, uCI] = ci_calc (stdDev, mean, sampleSize, cl)
% Confidence Interval Calculator

% Vector that hold different confidence level percentages
confLevel = [80, 85, 90, 95, 99, 99.5, 99.99];

% Vector that holds Z values
ZVals = [1.282, 1.440, 1.645, 1.960, 2.576, 2.807, 3.291];

% Finding Z Value
Z = ZVals(find(confLevel==cl));

% Calculating lower confidence interval
lCI = mean - ( Z * (stdDev / sqrt(sampleSize)) );

% Calculating upper confidence interval
uCI = mean + ( Z * (stdDev / sqrt(sampleSize)) );

end

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Sample Run:

calc (577.4, 37.4556, 100, 90) >> [ICI, uC1] = ci 1CI-57.527 uC1 132 . 44 7 -