Answer:
x ≈ - 1.83
Step-by-step explanation:
to solve for x in the question 1.1x + 1.2x - 5.4 = -10
we have
2.3x - 5.4 = -10
collect the like terms
2.3x = -10 + 5.4
2.3x = -4.2
divide both sides by the coefficient of x
2.3x/2.3 = -4.2/2.3
x = -1.826
x ≈ - 1.83
Answer:
We conclude that eighty percent of bike tires last at most 14.4 months.
Step-by-step explanation:
We know that a pair of bike tires can last 18 months if used every day.
We calculate how much eighty percent of the tire will last in months.
We have the following proportion:
We conclude that eighty percent of bike tires last at most 14.4 months.
3.5 think of it as 3.0
C. ——
2.0
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
