Can You List the Numbers - MPotW


> MPotW >



x




A list of twelve numbers have a range of eight, a mean, median & mode of five, if you picked one at random you had a fifty percent chance of a prime number, & there are as many even numbers as odd. List all twelve members.

-/|\-

Solution

We have twelve numbers, so n=12 & the mean is x_=Σxi12=5 Σxi =60 The median is five too but as there are an even number of elements the mode is the mean of the sixth & seventh element when listed in order, so median = x6+x7 2 =5 x6 + x7 =10

Furthermore, the mode is also five, so both x6 and x7 are five, perhaps more. The range is eight, so

x max - x min = 8

If the numbers are ordered this becomes

x 12 - x 1 = 8

Knowing the P(X=prime) = 0.5 so there must be six prime numbers (some are repeated, eg. five)

x1+ x2+ x3+ x4+ x5+ 5+ 5+ x8+ x9+ x10+ x11+ x1+ 8= 60 2⁢x1+ x2+ x3+ x4+ x5+ x8+ x9+ x10+ x11= 42

-oOo-


a MaS Tutor Icon