Answer:
a) P(X≥143)=0
b) This contradicts the study as getting a sample with this proportion is almost impossible (if the proportion of 68% is true).
Step-by-step explanation:
If we use the normal approximation to the binomial distribution we have the following parameters (mean and standard deviation):
Then, we can calculate the probability of X being equal or more than 143 using the z-score:
This contradicts the study as getting a sample with this proportion is almost impossible (if the proportion of 68% is true).
For the first system, we have
1 - 3x + 3y = -8
or
-3x + 3y = -9
The second equation, however, tells us
-3x + 3y = 13
but -9 ≠ 13, so this system has no solution.
For the second system, notice that multiplying both sides of
4x - 8y = 6
by 1/2 gives
2x - 4y = 3
which is identical to the other equation in the system. Then all point (x, y) that lie on this line are solutions to the system, meaning there are infinitely many solutions.
20 x .80 = 16
So the answer would be 16.
I hope this helps :)
Answer:
So here is the answer.
We represent h = hardwood and p = pine bark
Here is the equation: h + p = 176
2.75p + 3.50h = 520
Next, p = 176 -h (substitute)
2.75 (176-h) + 3.5h = 520
484 -2.75h + 3.5h = 520
3.5h-2.75h = 520 -484
0.75h = 36 (divide both by 0.75)
h = 48
Therefore, the number of hardwood sold is 48.
h + p = 176
p = 176-48
p= 128
The number of pine bark sold is 128.
Hope this helps :)
Step-by-step explanation:
