Answer and Step-by-step explanation:
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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:
12 books
Step-by-step explanation:
Since she has $15 and books come in a pack of four for $5, we can divide her money by the cost to see how many she can get ($15/$5) which gets us 3. but we have to remember the books come in a pack of four so we must multiply 3x4=12 books.
Answer:
answer c
Step-by-step explanation:
the two x-intercepts are (-4,0) and (2,0) so the factors of the equation are (x-2) and (x+4). if you multiply the factors it gives you the equation of the graph whic is x^2+2x-8 so c= -8 and b= 2
Answer:
−6
Step-by-step explanation: