Answer:
x = -9
Step-by-step explanation:
- 2(x + 7) = 4
Distribute
-2x -14 = 4
Add 14 to each side
-2x-14+14 = 4+14
-2x = 18
Divide each side by -2
-2x/-2 = 18/-2
x = -9
Answer:
The minimum sample size needed is 
. If n is a decimal number, it is rounded up to the next integer. 
is the standard deviation of the population.
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 Z-table as such z has a p-value of 
.
That is z with a pvalue of 
, so Z = 1.645.
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 must she select if she desires to be 90% confident that her estimate is within 4 ounces of the true mean?
A sample of n is needed, and n is found when M = 4. So
The minimum sample size needed is . If n is a decimal number, it is rounded up to the next integer. is the standard deviation of the population.
Answer:
1. 33%
2. 16%
3. 50%
Step-by-step explanation:
