2.13.2.3 ttest1

1 Brief Information
2 Command Line Usage
3 X-Function Execution Options
4 Variables
5 Description
6 Algorithm
7 References
8 Related X-Functions

Brief Information

One-Sample t-test

Command Line Usage

1. ttest1 irng:=Col(A);

2. ttest1 irng:=Col(A) mean:=10 tail:=1;

3. ttest1 irng:=Col(A) alpha:=0.05;

3. ttest1 irng:=Col(A) prob:=myprob;

X-Function Execution Options

Please refer to the page for additional option switches when accessing the x-function from script

Variables

Display Name	Variable Name	I/O and Type	Default Value	Description
Input	irng	Input Range	<active>	This variable specifies the input data range.
Hypothetical mean	mean	Input double	0	This variable specifies a value for the null hypothesis mean
Tail	tail	Input int	two	Alternative hypothesis specified by the tail. (Suppose m is the sample mean and m0 is the hypothetical mean.) Option list two:Two Tailed H0: m <> m0 Test whether the sample mean equals to the hypothetical mean upperUpper Tailed H0: m > m0 Test whether the sample mean is larger than the hypothetical mean lower:Lower Tailed H0: m < m0 Test whether the sample mean is less than the hypothetical mean.
Significance level	alpha	Input double	0.05	Set the significance level of the test
Statistic	stat	Output double	<unassigned>	This variable specifies the output for the t-test statistic
Degrees of freedom	df	Output double	<unassigned>	This variable specifies the output for the degrees of freedom for the sample data
P-value	prob	Output double	<unassigned>	This variable specifies the output for the associated p-value of the test.
Lower confidence limit	lcl	Output double	<unassigned>	This variable specifies the output for the lower confidence limit for the hypothetical mean of the sample data.
Upper confidence limit	ucl	Output double	<unassigned>	This variable specifies the output for the upper confidence limit for the hypothetical mean of the sample data.

Description

This function is LabTalk accessing only and performs one-sample t-test for a given dataset.

The one-sample Student's t-Test determines whether or not the mean of a sample taken from a normally distributed population is consistent with the hypothetical value for a given confidence level. By choosing a one- or two-tailed t-test, you can test how likely it is that the sample mean is greater than, less than, or equal to the true population mean. Note that the one-sample t-test is appropriate when the standard deviation of the entire population is unknown.

The t statistic value and p-value will be calculated to decide whether or not to reject the null hypothesis. The p-value is the probability that null hypothesis is true, and a small p-value suggests that you should reject it.

The confidence interval provides lower and upper limits for the possible value of the population mean. For a given significance level, $\alpha$ ., this interval indicates we have 100 $\times$ (1- $\alpha$ ) % confidence to say the true population mean falls within the interval.