The following sequence of numbers is arranged in increasing order: 1, x, x, x, y, y,9,16,18. Given that the mean and median are equal, and are also equal to twice the mode, the value of y is

Since the mode is x and the mean is twice the mode, the mean and median both equal 2x. The median is the fifth term in the nine-term sequence, so y = 2x. The sum is 1 + 3x + 2y + 9 + 16 + 18 = 44 + 3x + 2y, and the mean is this sum divided by 9, giving 2x = (44 + 7x)/9. Solving 18x = 44 + 7x yields x = 4, so y = 2 times 4 = 8.

• Thanks
• Wrong explanation