A is not linear A linear equation is an equation of a straight line, which means that the degree of a linear equation must be
for each of its variables. In this case, the degree of variable
Not Linear
Step-by-step explanation:
To solve a system of equations, we can add the two equations and solve for one of the remaining variables -- let's try to eliminate the variable when we add the two equations together.
Right now, there's a term in the first equation, and a term in the second equation, so if we add those together, we'll be able to eliminate the variable altogether and solve for .
However, when we also have a term in the first equation and term in the second equation, so adding these together will also eliminate the term, leaving a on the left-hand side of the equation.
If we add the two numbers on the right side of the equation, we get , which does not equal , meaning there are no solutions to this system of equations.
The sample size should be 250.
Our margin of error is 4%, or 0.04. We use the formula
To find the z-score:
Convert 98% to a decimal: 0.98
Subtract from 1: 1-0.98 = 0.02
Divide both sides by 2: 0.02/2 = 0.01
Subtract from 1: 1-0.01 = 0.99
Using a z-table (http://www.z-table.com) we see that this value has a z-score of approximately 2.33. Using this, our margin of error and our proportion, we have:
Divide both sides by 2.33:
Square both sides:
Multiply both sides by n:
Divide both sides to isolate n:
Answer:
Example:
A bag contains 3 black balls and 5 white balls. Paul picks a ball at random from the bag and replaces it back in the bag. He mixes the balls in the bag and then picks another ball at random from the bag.
a) Construct a probability tree of the problem.
b) Calculate the probability that Paul picks:
i) two black balls
ii) a black ball in his second draw
Solution:
tree diagram
a) Check that the probabilities in the last column add up to 1.
b) i) To find the probability of getting two black balls, first locate the B branch and then follow the second B branch. Since these are independent events we can multiply the probability of each branch.
ii) There are two outcomes where the second ball can be black.
Either (B, B) or (W, B)
From the probability tree diagram, we get:
P(second ball black)
= P(B, B) or P(W, B)
= P(B, B) + P(W, B)