The mean of the numbers 3, 6, 4, x and 7 is 5. Find the standard deviation.

1.2

Step-by-step explanation:

Since (3 + 6 + 4 + x + 7) / 5 = 5, then 3 + 6 + 4 + x + 7 equals 25. Adding, we have 20 + x = 25. Thus x = 5. Now we calculate how far each number is from the mean. 3 is 2 away. 6 is 1 away. 4 is also 1 away. 5 is 0 away, and 7 is 2 away. Now, we have to find the mean of this. (2 + 1 + 1 + 0 + 2) / 5 is equal to 6/5, which is 1.2