Since the Hypothesis Testing is being done on different values of the same variable, the technique that is used is paired/dependant t-test.
Here is the formula : (Observed Mean Difference - Expected Mean Difference)/Standard Error
Step 1 : You need to calculate the mean difference between the two variables of all the observations. This is the Observed Mean Difference.
Step 2: If you assume that the Null Hypothesis is true, the Expected Mean Difference is to be taken as 0.
Step 3: Standard Error is the variation in the standard deviation due to chance. This is calculated by dividing the standard deviation of the population by the sample size.
Step 4: Use these to compute the t-value.