Answer:
Step-by-step explanation:
Assuming there is a punitive removal of one point for an incorrect response.
Five undiscernable choices: 20% chance of guessing correctly -- Expectation: 0.20*(1) + 0.80*(-1) = -0.60
Four undiscernable choices: 25% chance of guessing correctly -- Expectation: 0.25*(1) + 0.75*(-1) = -0.50
I'll use 0.33 as an approzimation for 1/3
Three undiscernable choices: 33% chance of guessing correctly -- Expectation: 0.33*(1) + 0.67*(-1) = -0.33 <== The approximation is a little ugly.
Two undiscernable choices: 50% chance of guessing correctly -- Expectation: 0.50*(1) + 0.50*(-1) = 0.00
And thus we see that only if you can remove three is guessing neutral. There is no time when guessing is advantageous.
One Correct Answer: 100% chance of guessing correctly -- Expectation: 1.00*(1) + 0.00*(-1) = 1.00
First, a bit of housekeeping:
<span>The meaning of four consecutive even numbers is 15. Wouldn't that be "mean," not meaning? Very different concepts!
The greatest of these numbers is _______ a^1
"a^1" means "a to the first power. There are no powers in this problem statement. Perhaps you meant just "a" or "a_1" or a(1).
The least of these numbers is ______a^2.
No powers in this problem statement. Perhaps you meant a_2 or a(2)
In this problem you have four numbers. All are even, and there's a spacing of 2 units between each pair of numbers (consecutive even).
The mean, or arithmetic average, of these numbers is (a+b+c+d) / 4, where a, b, c and d represent the four consecutive even numbers. Here this mean is 15. The mean is most likely positioned between b anc c.
So here's what we have: a+b+c+d
------------- = 15
4
This is equivalent to a+b+c+d = 60.
Since the numbers a, b, c and d are consecutive even integers, let's try this:
a + (a+2) + (a+4) + (a+6) = 60. Then 4a+2+4+6=60, or 4a = 48, or a=12.
Then a=12, b=14, c=16 and d=18. Note how (12+14+16+18) / 4 = 15, which is the given mean.
We could also type, "a(1)=12, a(2)=14, a(3) = 16, and a(4) = 18.
</span>
Answer:
7.5 +9.63.
7.5+9.63. + N
17.13N
is the answer
Step-by-step explanation:
