Which test should be used one samples t test, independent samples t test or dependent samples t test
You may have heard that eating salt can influence people’s weight. Assume that the normal weight of 20-year-old females is 150 pounds. You obtain a sample of 20-year-old females (N = 12) who consumed salty foods and record their weight. determine whether salt intake affects weight.
To determine whether salt intake affects weight in this scenario, you can use the independent samples t-test.
The independent samples t-test is appropriate when you have two different groups or conditions that you want to compare. In your case, you have one group of 20-year-old females who consume salty foods (the experimental group) and another group of 20-year-old females with a normal weight of 150 pounds (the control group).
To conduct the t-test, you will need to follow these steps:
1. Null hypothesis (H0): There is no difference in weight between the two groups.
2. Alternative hypothesis (Ha): There is a difference in weight between the two groups.
3. Calculate the mean weight of the experimental group and the control group.
4. Calculate the standard deviation of the weights for both groups.
5. Determine the t-value using the formula:
t = (mean1 - mean2) / (pooled standard deviation * sqrt(1/n1 + 1/n2))
where mean1 is the mean weight of the experimental group, mean2 is the mean weight of the control group, n1 is the sample size of the experimental group, n2 is the sample size of the control group, and the pooled standard deviation is calculated using the formula:
pooled standard deviation = sqrt(((n1-1) * sd1^2 + (n2-1) * sd2^2) / (n1 + n2 - 2))
where sd1 is the standard deviation of the experimental group and sd2 is the standard deviation of the control group.
6. Find the degrees of freedom (df) using the formula:
df = n1 + n2 - 2
7. Calculate the p-value using the t-value and the degrees of freedom. This value will indicate the probability of obtaining the observed difference in weight by chance alone.
8. Compare the p-value to a predetermined significance level (e.g., 0.05) to determine whether the results are statistically significant. If the p-value is smaller than the significance level, you can reject the null hypothesis and conclude that there is a significant difference in weight between the two groups.
By following these steps and conducting an independent samples t-test, you can determine whether salt intake affects the weight of 20-year-old females in your sample.