How to Calculate One Sample in a T Test

The one-sample t test determines if the mean from the group under study is different from the population mean. Data for a one-sample t test is normally distributed. The samples from the population should be random, and sample size should be less than 30. The calculation for a one-sample t test gives a t value. This value is used in a standard t table taking into account the degrees of freedom. The degrees of freedom are the number in the experimental group minus 1.

Things You'll Need

• Experimental data
• Known population data
• Calculator
• Standard t tables

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Instructions

Calculate t Value

• 1

  Determine the null hypothesis. This should assume that there is no significant difference between the experimental mean and the population's mean.

• 2

  Calculate the average of the experimental group. Calculate the standard deviation of the experimental group.

• 3

  Subtract the average of the experimental group ROM the population's average. Divide by the standard deviation of the experimental group and multiply by the square root of the number in the experimental group.

• 4

  Take this figure which is a t value. Compare this t value with standard t tables. A p value of less than 0.05 would be considered statistically significant.