72 is the answer you are looking for here
Answer:
a: z = -1.936
b: 0.0265
d: z < -1.645
Reject H0 if z < -1.645
Step-by-step explanation:
We are given:
H0: µ = 20
HA: µ < 20
n = 60, sample mean: 19.6, σ = 1.6
Since the alternate hypothesis has a < sign in it, it is a left tailed test. The < or > sign in the alternate hypothesis points towards the rejection region.
For a: We need to calculate the test statistic for our situation. This is done with a z-score formula for samples.
For b: we need to use the z-score table to look up the p-value for the score we calculate in part a. The p-value is 0.0265. This means that there is only about a 2.65% chance that the sample values were a result of random chance.
For d: Since the significance level is 0.05, and this is a one tailed test, we have a critical value of z < - 1.645. This means that if the z-score we calculate in part a is less than -1.645, we will reject the null hypothesis
See attached photo for all the calculations!
Answer:
![-15](https://tex.z-dn.net/?f=-15)
Step-by-step explanation:
We can factor out a 1 from -3 to get
.
We know from simple arithmetic that
.
So, our answer is ![-1(15)=\boxed{-15}](https://tex.z-dn.net/?f=-1%2815%29%3D%5Cboxed%7B-15%7D)
Answer:
$0.80/oz
Step-by-step explanation:
$4 for 5 ounces
unit cost = price/weight = $4/(5 oz.) = $0.80/oz
It's not the difference of squares, rather it is the square of a difference. That leaves a perfect square trinomial, which narrows your selection to two choices. An expression with 2 terms is not a trinomial, so that further narrows your selection. The appropriate choice is
... (4xy -3z)² = 16x²y² -24xyz +9z², a perfect square trinomial
_____
The expression you have in your problem statement has no z term, so none of the choices is applicable to that one.