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:
m = -12 / 6 = -2 / 1 = -2
So its -2
The ratio should be written as:
mining:manufacturing:communication
Since there are three varieties of ratio's, then there is a specific answer for each. For the first example, the ratio is written as:
33/77:22/77:22/77
To find the integer ratio, divide all numbers with the smallest value, 22/77. The ratio becomes: 1.5:1:1
For the second example,
55/77:11/77:11/77
To find the integer ratio, divide all numbers with the smallest value, 11/77. The ratio becomes: 5:1:1
For the third example,
0:11/77:66/77
For this, exclude the ratio for mining because if you use this as the value, then all the numbers would be zero. Instead, divide using 11/77. The ratio becomes: 6:1.
