Answer:
Step-by-step explanation:
There are exponent rules I posted above that are being used here.
We have (3^-6)^-5
Since we have a power times a power, we multiply 6 and 5 to get -30. Look at the first example in the photo.
So, we're left with 3^-30.
If you look at the photo, there's a rule for negative exponents.
Take the inverse of the base number, so 3 in this case:
1 / 3
and then make the exponent positive after taking the inverse.
So, we should get 1 / 3^30
Hope this helps!
Answer:
A sample of 179 is needed.
Step-by-step explanation:
We have that to find our level, that is the subtraction of 1 by the confidence interval divided by 2. So:
Now, we have to find z in the Ztable as such z has a pvalue of .
That is z with a pvalue of , so Z = 1.44.
Now, find the margin of error M as such
In which is the standard deviation of the population and n is the size of the sample.
A previous study found that for an average family the variance is 1.69 gallon?
This means that
If they are using a 85% level of confidence, how large of a sample is required to estimate the mean usage of water?
A sample of n is needed, and n is found for M = 0.14. So
Rounding up
A sample of 179 is needed.