Answer: sigma is used for measuring Population Standard Deviation.
Step-by-step explanation:
The lower case Greek letter 'sigma' is denoted by the symbol ( 
).
This symbol indicates the Population Standard Deviation of the data. Standard deviation means how much variation or dispersion is there in our data. Squaring of standard deviation gives us Variance which is denoted by the symbol 
.
Formula for Population Standard deviation ( ) is = 
,
where 
= each value from our list of data
= Population mean of data
N = Number of observations in our data
Standard deviation can never be negative and it is very much sensitive to outliers in our data.
About 3.5 inches of snow would’ve fallen in 10 hours
Answer: W= -51
Step-by-step explanation:
Isolate the variable by dividing each side by factors that don't contain the variable.
2x(x - 8) -5(x - 8)
= (x - 8)(2x - 5)
Answer:
554 executives should be surveyed.
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 = 1.96.
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.
Standard deviation of 3 hours.
This means that 
The 95% level of confidence is to be used. How many executives should be surveyed?
n executives should be surveyed, and n is found with 
. So
Rounding up:
554 executives should be surveyed.
