Answer:
b
Step-by-step explanation:
So we can start with the full of possibilities and eliminate them one by one.
The full set is {0,1,2,3,4,5,6,7,8,9}.
Now we know that any prime greater than 2 is odd as otherwise it would have 2 as a factor, so we can eliminate all of these digits that would be an even number, leaving:
{1,3,5,7,9}
We also know that any prime greater than 5 cannot be a multiple of 5 and that all numbers with 5 in the digits are a multiple of 5, so we can eliminate 5.
{1,3,7,9}
We know that 11,13,17 and 19 are all primes, so we cannot eliminate any more of these, leaving the set:
{1,3,7,9} as our answer.
To find the mean (average), we first need to add up all the test scores (14 + 19 + 19 + 20 + 16 + 18 + 15 + 17 + 12 = 150). Then, we need to divide that number (150) by the number of numbers in the data set (9 in this case). So the mean of these test scores is about 16.6666666667.
What do you need to help?
