Answer: The required value of x is 39.1.
Step-by-step explanation: Given that the mean of the following data set is 35.

We are to find the value of x.
To find the mean of a data set, we need to add all the values together and divide by the number of values in the set.
The sum of all the values in the given data is given by

And the total number of values in the given data = 4.
Therefore, the MEAN of the data is

Thus, the required value of x is 39.1.