2.13.2.3 ttest1
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
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Variable Name
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I/O and Type
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Default Value
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Description
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Input
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irng
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Input
Range
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<active>
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This variable specifies the input data range.
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Hypothetical mean
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mean
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Input
double
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0
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This variable specifies a value for the null hypothesis mean
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Tail
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tail
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Input
int
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two
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Alternative hypothesis specified by the tail. (Suppose m is the sample mean and m0 is the hypothetical mean.)
Option list
- H0: m <> m0
- Test whether the sample mean equals to the hypothetical mean
- H0: m > m0
- Test whether the sample mean is larger than the hypothetical mean
- H0: m < m0
- Test whether the sample mean is less than the hypothetical mean.
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Significance level
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alpha
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Input
double
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0.05
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Set the significance level of the test
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Statistic
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stat
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Output
double
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<unassigned>
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This variable specifies the output for the t-test statistic
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Degrees of freedom
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df
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Output
double
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<unassigned>
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This variable specifies the output for the degrees of freedom for the sample data
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P-value
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prob
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Output
double
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<unassigned>
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This variable specifies the output for the associated p-value of the test.
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Lower confidence limit
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lcl
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Output
double
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<unassigned>
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This variable specifies the output for the lower confidence limit for the hypothetical mean of the sample data.
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Upper confidence limit
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ucl
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Output
double
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<unassigned>
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This variable specifies the output for the upper confidence limit for the hypothetical mean of the sample data.
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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, ., this interval indicates we have 100 (1-) % confidence to say the true population mean falls within the interval.
Algorithm
Detail algorithms please read the help of OneSampletTest
References
Snedecor, George W. and Cochran, William G. (1989), Statistical Methods, Eighth Edition, Iowa State University Press.
Related X-Functions
ttest2, ttestpair
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