A population with a mean of u =10 has EX= 250. How many scores are in the population?

To determine the number of scores in the population, we need to use the formula for expected value (EX) of a population.

The formula for expected value is given by:
EX = Σ(x * P(x))

Where:
EX is the expected value
Σ indicates a sum over all possible values of x
x is the value
P(x) is the probability of that value occurring

In this case, we are given that the mean (u) is 10 and the expected value (EX) is 250.

Since the expected value is given, we can set up the equation:

250 = Σ(x * P(x))

To calculate the sum, we need to know all the possible values of x and their probabilities. Unfortunately, this information is not provided, so it is impossible to determine the number of scores in the population based solely on the given information.