The graph of function like that may may never cross the x-axis,
so the function could have no real zeros.
If it does have zeros, they will come in pairs,
because "what goes up must come down" and vice versa.
Of course the function cannot have more zeros than its degree.
For example, a polynomial function of degree 6 could have 0, 2, 4, or 6 real zeros.
5/20 = 1/4. All the rest of the fractions reduce to 1/5.
3) median and mode!
Explanation:
Median- 3,4,5,(5),7,9,19
Mode- 5 is repeated.
For sake of convenience, reverse the series, then it would be:
21,19,17.....7
a=21, d = -2,
s(4) = 4/2 (21+15)
s(4)=2(36)
s(4) = 72