Answer:
Step-by-step explanation:
Hello!
For me, the first step to any statistics exercise is to determine what is the variable of interest and it's distribution.
In this example the variable is:
X: height of a college student. (cm)
There is no information about the variable distribution. To estimate the population mean you need a variable with at least a normal distribution since the mean is a parameter of it.
The option you have is to apply the Central Limit Theorem.
The central limit theorem states that if you have a population with probability function f(X;μ,δ²) from which a random sample of size n is selected. Then the distribution of the sample mean tends to the normal distribution with mean μ and variance δ²/n when the sample size tends to infinity.
As a rule, a sample of size greater than or equal to 30 is considered sufficient to apply the theorem and use the approximation.
The sample size in this exercise is n=50 so we can apply the theorem and approximate the distribution of the sample mean to normal:
X[bar]~~N(μ;σ2/n)
Thanks to this approximation you can use an approximation of the standard normal to calculate the confidence interval:
98% CI
1 - α: 0.98
⇒α: 0.02
α/2: 0.01
X[bar] ± 
174.5 ± 
[172.22; 176.78]
With a confidence level of 98%, you'd expect that the true average height of college students will be contained in the interval [172.22; 176.78].
I hope it helps!
Answer:
Step-by-step explanation:
so first we need to find the height so by splitting the isosceles triangle into two right-angled triangles and then applying Pythagoras' Theorem to one of them.
We now know the height of the triangle and can use this to go back and find the area of the isosceles triangle.
area of triangle = 
x base x height
area of triangle = x 10 x 12
area of triangle = 60
Answer:
the correct answer is A
Step-by-step explanation:
Answer:
See attached
Step-by-step explanation:
When there is a lot of repetitive calculation to do, I like to let a spreadsheet or graphing calculator do it. The attached shows a spreadsheet that computes all the values you're asked to find.
For a linear equation in standard form, ax +by = c
- the x-intercept is: c/a
- the y-intercept is: c/b
- the slope is: m = -a/b
Of course, the slope-intercept form of the equation is ...
y = (slope)·x + (y-intercept)
and the values of the various points on the graph can be computed from that equation.
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You will note that the last two equations describe the same line.
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<em>Note on spreadsheet formulas</em>
When you put the formulas into the spreadsheet, make sure to fix the column number or row number of the values you're computing, as appropriate. For example, the y-values in the different columns always use the slope from the slope column (fixed), the y-intercept from that column (fixed), and the x-value from the top row (fixed). If you make the cell references relative instead of fixed, you will get wrong answers.
