Answer:
4
Step-by-step explanation:
The z-score is calculated by the following formula
z=(x-μ)/σ
where
μ=Population mean
σ=Population standard deviation
If the z-score for a specific sample mean is discussed then z-score is computed as
z=xbar-μ/σxbar.
where
μ=Population mean
σxbar=Sample standard deviation
As the population mean and mean of sampling distribution of mean are equal so, μ is used in above equation.
Now, the z-score is given
1.5=xbar-μ/σxbar
σxbar=xbar-μ/1.5.
Also we know that z-score corresponds to a score that is 6 points above mean which means that xbar-μ=6.
σxbar=6/1.5
σxbar=4.
Thus, the required sample standard deviation is 4.
Add like terms on the same side:
-10 + 8x = -56
Add ten to both sides
-10 + 8x + 10 = -56 +10
Simplify:
8x = -46
Divide both side by 8
8x/8 = -46/8
Simplify
x = - 5.75
The answer is x = -5.75
(The answer can also be written as -23/4 or -5 3/4)
Answer:
9 boxes
Step-by-step explanation:
Boxes of Cereal 3 for the price of 2, the the price of the 3 boxes of cereals must be : 2 × £2.89 = £5.78
Boxes Megan can buy for the offer = £20 ÷ £5.78 = 3.46 (to 3 s.f.)≈ 3
3 × 3 =9 packs
But they actually only cost : 3 × £5.78 = £17.34
Therefore after buying the offer Megan has £20 - £17.34 = £ 2.66 left, which is not enough to buy a single pack, so the answer is 9.
Answer:
x=9
Step-by-step explanation:
We have two similar triangles because both lines are parallel, use proportions to solve:
