Answer:
Correct option A
Step-by-step explanation:
Average rate = 260/4 = 65 mph
It increases by 12mph
So 65+12 = 77 mph
Correct option A
114/6=9 parts per minute. 9 parts * 15 minutes= 135 parts
Put the numbers in order
6,7,15,36,41,43,47,49
Q1 = (7 + 15) / 2 = 22/2 = 11 <== first quartile
Q2 = (36 + 41) / 2 = 77/2 = 38.5 <== median
Q3 = (43 + 47) / 2 = 90/2 = 45 <== third quartile
difference of largest value and median.....(49 - 38.5) = 10.5
Consider the trinomial 
1. Find the discriminant:

2. Find the roots of given trinomial:

3. Conclusion: given trinomial has two different real roots.