Answer:
-35j-35
Step-by-step explanation:
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.
X > -4 is the answer to the inequality
F(x) = 3x² + 6x - 1
The graph is a parabola open upward (a= 3>0) with a minimum.
Calculate the vertex:
x = -b/2a → x = -6/(2.3) = -1. Then the axis of symmetry is x = - 1
Now to calculate the minimum, plugin the value of x:
y = 3x² + 6x - 1
y = 3(-1)² + 6(-1) -1
y= 3 - 6 -1 and y = - 4,
Ten the vertex (minimum) is at (-1,- 4)
Answer:
$0.30 + $0.03n > $0.02 + $0.02n
Step-by-step explanation:
company x = $0.30 + $0.03n
company y = $0.02 + $0.02n
$0.30 + $0.03n > $0.02 + $0.02n