Answer:
b. Because the probability of being 15 or more correct is 0.0207, it is likely that she is just guessing at the questions.
Step-by-step explanation:
-This is a binomial probability distribution with p=0.5, n=20 and x=15.
The function is expressed as:

We calculate the probability of guessing 15 or more correctly:

The probability of passing, guessing 15+ correctly, is 0.0207. This probability is very low and it is it is likely that she is just guessing at the questions
Answer:
18.95
Step-by-step explanation:
ln 2 x ln (4x) = 3
ln 4x = = 3 / ln 2
ln4x = 3 / 0.69315 = 4.3281
4x = e^4.328 = 75.80
x = 18.95.
8x +9 + 15-8x is -32 it’s that easy
Answer: x= 1 , y = 7
Step-by-step explanation:
y = -6x + 13 ................. equation 1
y = 3x + 4 ................ equation 2
substitute y = 3x + 4 into equation 1 , then we have
3x + 4 = - 6x + 13
collect the like terms , we have
3x + 6x = 13 - 4
9x = 9
x = 1
substitute x = 1 into equation 2 , we have
y = 3(1) + 4
y = 3 + 4
y = 7
Therefore : x = 1 and y = 7