Answer:
number 4
Step-by-step explanation:
let me know if i am worng and thank you
So the mean is 72.97
We need to subtract the mean from each value and square it.
(65-72.97)^2= 63.5209
(68-72.97)^2=24.7009
(69-72.97)^2=15.7609
(70-72.97)^2=8.8209
(71-72.97)^2= 3.8809
(72-72.97)^2=0.9409
(90-72.97)^2=290.0209
(95-72.97)^2=485.3209
Now we add up the new values ( also consider their frequency) and find their mean.
Add the values
63.5209+(2 •24.7009=49.4018)+(5•15.7609=78.8045)+(8•8.8209=70.5672)+(7•3.8809=27.1663)+(3•0.9409=2.8227)+(2•290.0209=580.0418)+(2•485.3209=970.6418)= 1,842.967
Divide by total numburs to find the mean
1,842.967/ 30=61.43223333
The standar deviation is the square root of the mean so is
Square root of 61.43223333=7.837871735
Round to the nearest tenth
Standard Deviation is 7.8
now, there are 12 months in a year, so 18 months is really 18/12 of a year, thus
Answer:
This should be parallel.
Step-by-step explanation:
Two lines are said to be parallel only if their slope matches. They are said to be perpendicular only if the slopes are negative reciprocals.
Here, you should put both equations in slope intercept form which is y=mx+b. The letter "M" represents the slope of both equations.
2y-6=3x+4 turns into 2y=3x+10 after adding 6 and into y=3/2x+5 after dividing the equation by 2. The slope for this equation is 3/2.
8y=12x+8 must be divided by 8 to be in slope intercept form. This equation becomes y=3/2x+1. Here the slope is also 3/2.
The slopes for each equation match making these lines parallel.