I got it its this answer i used mathpapa for this
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:
Step-by-step explanation:
=-9+7i+5+i
=-4+8i
Answer:
15 hours.
Step-by-step explanation:
We first need to see how much money Rose would earn if she sold the 10 pendents, so we will multiply 4×10.
4×10=40
Now we know, she already has 40 dollars of the 160 dollars she needs.
To find out how much she needs left, we will subtract 40 from 160.
160-40=120
She needs a total of 120 more dollars from working.
To find out how many hours she needs to work, we will divide 120 by 8.
120÷8=15.
In conclusion, she needs to work for at least15 hours to receive enough money.Please help me by marking this brainliest, and giving a thanks!
