100% = Certain (no matter what.. it's going to happen)
75/100 = Likely (has a high chance of happening)
5/10 = Equally likely (can happen, or might not)
1/4 = Unlikely (might not happen)
0.0 = Impossible
hope this helps
Answer:
A) 50
B) 20
C) 20
Step-by-step explanation:
To solve the first question, we can multiply both sides by 10.
Thus, we get:
6x = 300.
Then, divide by 6, to get x:
x = 50.
You can do the same thing to all of these questions.
I've already checked the answers, but if you don't trust them, just pluck the values in.
For example, let's check the answer for question A.
0.6*50 is supposed to equal 30.
Does it equal? Yes, so we know that the answer is correct.
You don't even have to look up the definition of 'standard deviation'. You only
have to remember that 'smaller standard deviation' means 'less spread-out'.
First, let's find the mean (average). It's not supposed to change:
1/7th of (65 + 71 + 77 + 80 + 82 + 90 + 96) = 561/7 = <u>80 and 1/7</u> .
Now, just pick 7 scores that total 561 and are all bunched up.
The easiest way would be 80, 80, 80, 80, 80, 80, 81 .
But that's so easy that it feels like cheating.
Let's say <u>77, 78, 79, 80, 81, 82, and 84</u> .
First we'll do two basic steps. Step 1 is to subtract 18 from both sides. After that, divide both sides by 2 to get x^2 all by itself. Let's do those two steps now
2x^2+18 = 10
2x^2+18-18 = 10-18 <<--- step 1
2x^2 = -8
(2x^2)/2 = -8/2 <<--- step 2
x^2 = -4
At this point, it should be fairly clear there are no solutions. How can we tell? By remembering that x^2 is never negative as long as x is real.
Using the rule that negative times negative is a positive value, it is impossible to square a real numbered value and get a negative result.
For example
2^2 = 2*2 = 4
8^2 = 8*8 = 64
(-10)^2 = (-10)*(-10) = 100
(-14)^2 = (-14)*(-14) = 196
No matter what value we pick, the result is positive. The only exception is that 0^2 = 0 is neither positive nor negative.
So x^2 = -4 has no real solutions. Taking the square root of both sides leads to
x^2 = -4
sqrt(x^2) = sqrt(-4)
|x| = sqrt(4)*sqrt(-1)
|x| = 2*i
x = 2i or x = -2i
which are complex non-real values
