JAMB Mathematics 2022 Paper

Concept:The mean of a set of values is found by dividing the sum of the values by the number of values.Explanation:The four values are $2x$, $4x$, $2x - 13$, and $6x$.Add them together:$$2x + 4x + (2x - 13) + 6x = 14x - 13$$Since there are 4 values and the mean is 4, we write:$$\frac{14x - 13}{4} = 4$$Multiply both sides by 4:$$14x - 13 = 16$$Add 13 to both sides:$$14x = 29$$Divide both sides by 14:$$x = \frac{29}{14} \approx 2.07$$Substituting this value gives a mean of exactly 4, but it is not listed among the given options.Answer:$$x = \frac{29}{14} \approx 2.07$$