Answer:
20.25
Step-by-step explanation:
45x.40=20.25
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
Answer:
proportional
Step-by-step explanation:
all are multiplied by 3
Answer:
I think answer is 3
Step-by-step explanation:
BD = DA
BE = EC
Now, BD/BE = DA/EC
or, x + 5/2x = 4/3
or, 3x + 15 = 8x
or, 15 = 8x - 3x
or, 15 = 5x
or, 15/5 = x
or, 3 = x
Therefore x = 3 <u>Ans</u>
