2(-3-7)+5= <span>2(-10)+5= -20 + 5= -15
-15 is your final answer</span>
Answer:
The proportion of piano prices higher than the electric piano is 98.3%
Step-by-step explanation:
The first thing to do here is to calculate the standard score of the price of the electric piano given.
Mathematically, this is
z-score = (x-mean)/SD
where mean is 3000 and SD is 200, x is 2576
z-score = (2576-3000)/200 = -2.12
Now we proceed to calculate the probability of this z-score
The probability we are trying to calculate is
P( x > $2576) or simply P ( z > -2.12)
Using standard score probability calculator or table, we have
P(x>2576) = 1 - P(x<2576)
But, P(x<2576) = 0.017003
P(x>2576) = 1 - P(x<2576) = 0.983
This is same as 98.3%
Answer:
Since b^2 -4ac = 256 we have 2 real distinct root roots
Step-by-step explanation:
4x^2+12x=7
We need to subtract 7 to get it in the proper form
4x^2+12x-7=7-7
4x^2+12x-7=0
The discriminant is b^2 -4ac
when the equation is ax^2 +bx+c
so a =4 b=12 and c=-7
(12)^2 - 4(4)(-7)
144 +112
256
If b^2 -4ac > 0 we have 2 real distinct roots
If b^2 -4ac = 0 we have one real root
If b^2 -4ac < 0 we have two complex root
Since b^2 -4ac = 256 we have 2 real distinct root roots
