When asked for standard deviation when dealing with grouped data for linear regression, do you give them for each the x and y variable or is there a way to configure for grouped data set? I have a Ti 84 plus calculator
To calculate the standard deviation when dealing with grouped data for linear regression, you need to consider both the x and y variables separately. However, if you have a TI-84 Plus calculator, there is no direct function for calculating standard deviation for grouped data. But you can compute it by following these steps:
1. Enter your data into two lists on your calculator, one for the x variable and the other for the y variable.
2. Create another list for the frequency of each data point in the dataset. For example, if you have a grouped data set with intervals [0, 10), [10, 20), [20, 30), and so on, you would have a corresponding frequency for each interval.
3. Multiply each data point by its frequency to get the repeated values and store them in new lists.
4. Calculate the mean (average) of both the x and y variables separately using the repeated values.
5. Calculate the squared deviation of each repeated value from its respective mean value.
6. Multiply each squared deviation by its corresponding frequency and store them in new lists.
7. Sum up all the values in the new lists from step 6.
8. Calculate the total frequency by summing up all the frequencies from step 2.
9. Divide the sums obtained in step 7 by the total frequency obtained in step 8 to get the sum of squared deviations.
10. Take the square root of the sum of squared deviations divided by (total frequency - 1) to get the standard deviation for both the x and y variables.
It's important to note that the TI-84 Plus calculator does not provide a built-in function for directly calculating standard deviation for grouped data. However, by performing the steps mentioned above, you can find the standard deviation using the calculator.