When ever you have percentages, it should be helpful to bear in mind you can express them as multipliers. In this case, it will be helpful.
So, if we let:
a = test score
b = target score
then, using the information given:
a = 1.1b + 1
a = 1.15b - 3
and we get simultaneous equations.
'1.1' and '1.15' are the multipliers that I got using the percentages. Multiplying a value by 1.1 is the equivalent of increasing the value by 10%. If you multiplied it by 0.1 (which is the same as dividing by 10), you would get just 10% of the value.
Back to the simultaneous equations, we can just solve them now:
There are a number of ways to do this but I will use my preferred method:
Rearrange to express in terms of b:
a = 1.1b + 1
then b = (a - 1)/1.1
a = 1.15b - 3
then b = (a + 3)/1.15
Since they are both equal to b, they are of the same value so we can set them equal to each other and solve for a:
(a - 1)/1.1 = (a + 3)/1.15
1.15 * (a - 1) = 1.1 * (a + 3)
1.15a - 1.15 = 1.1a + 3.3
0.05a = 4.45
a = 89
Answer:
We conclude that the mean nicotine content is less than 31.7 milligrams for this brand of cigarette.
Step-by-step explanation:
We are given the following in the question:
Population mean, μ = 31.7 milligrams
Sample mean,
= 28.5 milligrams
Sample size, n = 9
Alpha, α = 0.05
Sample standard deviation, s = 2.8 milligrams
First, we design the null and the alternate hypothesis

We use One-tailed t test to perform this hypothesis.
Formula:

Putting all the values, we have

Now,
Since,
We fail to accept the null hypothesis and accept the alternate hypothesis. We conclude that the mean nicotine content is less than 31.7 milligrams for this brand of cigarette.
Answer:
It would be the first answer.
Step-by-step explanation:
y=-2x^2+4x-2
y=-2(-1)^2+4(-1)-2
y=-2(1)-4-2
y=-2-4-2
y=-6-2
y=-8
(-1,-8)
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If they saved £29 all together, and if each of them saved the same amount,
then each saved £29/4 = £7.25 or £7 and 25p.
(Before decimalization in 1971, £7.25 would have been £7 and 5s .)
To figure out the cost per cookie, divide $2.49 by 3. The cost per 1 cookie (column 1) would be .83 cents.
To figure out the cost of 20 cookies, multiply 20 x .83 cents. The answer is 20 cookies would cost $16.60
To figure out how many cookies would cost $145,25, divide $145.25 by .83 cents. The answer is 175 cookies would cost $145.25