Final answer:
To find y when the mean of the numbers 20, 2y, 25, y, and 30 is 27, set up and solve the equation resulting in y = 20.
Step-by-step explanation:
To calculate for y given that the mean of 20, 2y, 25, y, and 30 is 27, you can set up an equation based on the definition of mean. The mean is calculated by summing all the values in the set and then dividing by the number of values. In this case, we have 5 values. The equation to find y is as follows:
(20 + 2y + 25 + y + 30) / 5 = 27
Now, simplify and solve for y:
20 + 3y + 55 = 135
3y + 75 = 135
3y = 135 - 75
3y = 60
y = 60 / 3
y = 20
Therefore, the value of y that makes the mean of the set equal to 27 is 20.