public static tTestOneSample ( number $Hₐ, number $s, integer $n, number $H₀ ) : array | ||
$Hₐ | number | Alternate hypothesis (M Sample mean) |
$s | number | SD of sample |
$n | integer | Sample size |
$H₀ | number | Null hypothesis (μ₀ Population mean) |
return | array | [ z => z score p1 => one-tailed p value (left or right tail depends on how Hₐ differs from H₀) p2 => two-tailed p value ] |
public static function tTestOneSample($Hₐ, $s, $n, $H₀) : array
{
// Calculate test statistic t
$t = self::tScore($Hₐ, $s, $n, $H₀);
// Degrees of freedom
$ν = $n - 1;
// One- and two-tailed P values
if ($Hₐ < $H₀) {
$p1 = StudentT::CDF($t, $ν);
} else {
$p1 = StudentT::above($t, $ν);
}
$p2 = StudentT::outside(-abs($t), abs($t), $ν);
return ['t' => $t, 'p1' => $p1, 'p2' => $p2];
}