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Answer:
a = -1
Step-by-step explanation:
The general equation for a straight line is y = mx+c, where m is the gradient/ slope, so m = -5. The first thing we need to do is find c, which we do by plugging in the x and y values that we already know: y = 7 and x = -2
7 = -5*(-2) + c
7 = 10 + c
c = 7-10 = -3
Now, we have the general equation of y = -5x -3 and we can use this to find a.
We'll treat a as x and y will be equal to 2:
2 = -5a -3
5 = -5a (Divide both sides by 5)
-a = 1 (now by -1)
a = -1
Answer:
The 99% confidence interval is
Step-by-step explanation:
From the question we are told that
The sample size is n = 100
The sample mean is 
The population standard deviation is
From the question we are told the confidence level is 99% , hence the level of significance is
=>
Generally from the normal distribution table the critical value of
is
Generally the margin of error is mathematically represented as

=>
Generally 95% confidence interval is mathematically represented as
=>
=>
Answer: D
Explanation:
Since we don't know the y-value of the vertex, let's do this an easy way: plugging in.
Let's use the y intercept since that would be the easiest. Since x=0, the terms with x cancel, and you will get a leading result of -5
A) results in 2, so eliminate it
B) results in -2, so eliminate it
C) results in 5, so eliminate it
D) results in -5, so keep it
Since D was the only one that worked, that is our correct answer.