Answer:
Step-by-step explanation:
Hello!
The mean is a measurement of central tendency that shows what is the most expected value of the variable. The standard deviation is a measurement of variability, it shows you how distant or dispersed are the values of a certain population or sample in regards to the value of the mean.
In this example the variable is X: score obtained on a math test.
It's mean is μ= 52 and its standard deviation is σ= 10
To know how many standard deviations away is a value of X concerning the mean you have to first subtract the mean to the value of X, X - μ, and then you have to divide it by σ:
(X - μ)/ σ
If X=76
(76 - 52)/ 10= 2.4
The score obtained by Andrea is 2.4σ away from the mean.
I hope it helps!
Answer: 8.1ft
Step-by-step explanation:
It may help to draw it out but for this question you would have to use pythagoras' theorem.
The formula for the shorter side is a²=c²-b²
The height of this triangle is 4ft (b) and the hypotenuse (the diagonal that stretches from the top to the bottom) is 9ft (c).
When we put the numbers in the formula you get a²=9²-4²
9²=81
4²=16
a²=81-16
a²=65
Then because we want to find a on it's own you would have to square root 65 which is 8.1 (to the nearest tenth)
One major problem is that you're not keeping the units like I showed you.
I think you have everything there, except that I have no idea what that '168'
is all about.
Here it is with the units:
(1million seconds / 1)x(1min/60sec)x(1hr/60min)x(1 day/24hr)x(1 yr/365da)
= (1,000,000 x year) / (60 x 60 x 24 x 365) = <em>0.03171 year</em>
Except for that screwy mysterious '168', you have everything there,
and in the right place. Again, I'm going to say that you didn't realize
it, because you dropped all the units and suddenly all you saw was a
bunch of numbers in front of you.
Tue answer is 2.6 !................................,..,.,.,.,.,.,.,.
