prob stat: One sample of n=4 scores has a mean of M=10, &

a second sample of n=10 scores has a mean of M=20. If the 2 samples are combined then what value will be obtained for the mean of the combined sample? a) Equal to 15 b) Greater than 15 but less than 20 c) Less than 15 but more than 10 d)None of the other choices is correct