Answer:
1.
Step-by-step explanation:
We are being told that:
A scientist is hoping to compare the mean levels of DDT toxin found in three species of fish in a local river.
He randomly samples 50 of each species to use in the analysis.
i.e sample size n = 50
For each fish, he measures the amount of DDT toxin present. The amount of DDT toxin present will be use to rank the species based on the mean level of toxin.
From the information above, we will realize that the factors that are present in this study is just only one and which is the amount of DDT in a Fish because, it is the major focus in this question.
X^2 - 10x - 9 = 0
first we will move the constant term to the other side
x^2 - 10x = 9
then, to both sides we will add the number that makes the polynomial on the left a perfect square trinomial. Take half of the coefficient of x, then square it. half of the coefficient of x (-10) is -5, and -5 squared is 25. so:
x^2 - 10x + 25 = 34
factor the perfect square trinomial
(x - 5)^2 = 34
x - 5 = plus or minus sqrt(34)
x = 5 plus or minus sqrt(34)
It is 3:4 red marbles to total number of marbles
A graphing calculator shows it has 3 real solutions, near x ∈ {-3.033, 1.241, 2.964}.
