Answer: x = 10
Step-by-step explanation:
(
4
x
−
5
)
=
7
(
x
−
5
)
Simplify 7
(
x
−
5
)
.
4
x
−
5
=
7
x
−
35
Move all terms containing x to the left side of the equation.
−
3
x
−
5
=
−
35
Move all terms not containing x to the right side of the equation.
−
3
x
=
−
30
Divide each term by −
3 and simplify.
x
=
10
<span>3(a+(6x)y) was clearly multiplied out as seen by the 3a and 18xy, so the distributive property was used there. In addition, the commutative and associative properties state that you can rearrange sums, so those were used too </span><span />
Answer:
200,000
Step-by-step explanation:
I think this is the answer
121 is big enough to assume normality and not worry about the t distribution. By the 68-95-99.7 rule a 95% confidence interval includes plus or minus two standard deviations. So 95% of the cars will be in the mph range

The question is a bit vague, but it seems we're being asked for the 95% confidence interval on the average of 121 cars. The 121 is a hint of course.
The standard deviation of the average is in general the standard deviation of the individual samples divided by the square root of n:

So repeating our experiment of taking the average 121 cars over and over, we expect 95% of the averages to be in the mph range

That's probably the answer they're looking for.