Answer:
a) The Sample Standard deviation "measures the spread of a data distribution. It measures the typical distance between each data point and the mean"
b) 
Step-by-step explanation:
Previous concepts
The central limit theorem states that "if we have a population with mean μ and standard deviation σ and take sufficiently large random samples from the population with replacement, then the distribution of the sample means will be approximately normally distributed. This will hold true regardless of whether the source population is normal or skewed, provided the sample size is sufficiently large".
Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".
Let X the random variable who represents the scores. We know from the problem that the distribution for the random variable X is given by:

We take a sample of n=25 nails.
From the central limit theorem we know that the distribution for the sample mean
is given by:

Part a
The Sample Standard deviation "measures the spread of a data distribution. It measures the typical distance between each data point and the mean"
Part b
The standard error is given by:

And replacing we got:

X=-6
You plus in x as -6 and you already know that y=5x and you plug in x=-6
It should look like 2(-6)-5(-6)=18
Answer:
(x + 4)(x + 5)
Step-by-step explanation:
The given equation in the form of polynomial is:
Factorizing the above given equation, we get
Taking x+5 common, we have
which is the required factorised form.
Therefore the factors of the given polynomial are .
Answer: Wall 1 & 2 : 26 ft by 9 ft
Wall 3 : 18 ft by 9 ft
Area 1 : 26 ft x 9 ft = 234 ft²
Area 2 : 26 ft x 9 ft = 234 ft²
Area 3 : 18 ft x 9 ft = 162 ft²
Total Area : 234 ft² + 234 ft² + 162 ft² = 630 ft²
1 Gallon = 250 ft²
630 ft² ÷ 250 ft² per gallon = 2.52 gallons