Answer:
We need a sample size of at least 719
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
.
So it is z with a pvalue of
, so 
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.
How large a sample size is required to vary population mean within 0.30 seat of the sample mean with 95% confidence interval?
This is at least n, in which n is found when
. So






Rouding up
We need a sample size of at least 719
Answer:
yus
Step-by-step explanation:
Answer:

Step-by-step explanation:
1. 10xy · 4xy^3 = 
2. 10xy · -7xy = 
3. 10xy · 9y^2 =
Final step: add up all of those values together to make an equation!
Answer:

Final Answer: 
Answer:
12.5 minutes
Step-by-step explanation:
it takes 5 minutes to cool 10 degrees
after ten minutes it would be 20 degrees less
then after 2.5 minutes it would be 5 degrees less
so it would take you 12.5 minutes to get 25 degrees less