S1=$70/20gal=$3.50 per gallon
s2=$33.50/(50/4)gal=$2.68 per gallon
s3=$48.75/(15+8)gal=$2.12 per gallon
So supplier #3 has the best deal.
Given:
p = 90% = 0.9, the probability that the seed grows into a healthy plant.
Therefore
q = 1 - p = 0.1, the probability that the seed will not grow into a healthy plant.
n = 7, the number of seeds planted.
Let r = 4, expected number of seeds that will grow.
Use the Binomial distribution to determine
P(4 of 7 seeds will grow) = ₇C₄ p⁴q⁽⁷⁻⁴)
= 35*(0.9⁴)*(0.1³)
= 0.023
P(4 of 7 seeds will not grow) = 1 - P(4 of 7 seeds will grow)
= 1 - 0.023
= 0.977 or 97.7%
Answer: 97.7%
Note that c is the hypotenuse of the blue triangle, and that the Pyth. Thm. states that (length of one leg)^2 + (length of the other leg)^2 = (hyp)^2.
Therefore, (hyp)^2 = c^2 = [2sqrt(x^2+3x)]^2 + 3^2, or
= 4(x^2+3x) + 9, or
= 4x^2 + 12x + 9 = (2x+3)^2
Taking the sqrt of both sides, c = plus or minus (2x+3). Eliminate -(2x+3) because the middle term of the square of this would be negative, in conflict with the given +12x.
c=2x+3 is the correct answer.