If the length of a rectangle is 3m longer than its width, then:
L=W+3
Is the area really 154^2? Or is it 154m^2? If yes, then:
A=LW
154=(W+3)(W)
154=(W^2+3W)
0=W^2+3W-154
0=(W-11)(W+14)
This means either (W-11) or (W+14) is equal to zero so:
W=11 and W=-14
To find out let's substitute the numbers:
154=(11+3)(11)
154=154
Therefore, the width of the rectangle is 11m
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.
Answer:
Company A:
c = 40 + 2s
Company B:
c = 20 + 4s
Equal costs => 40 + 2s = 20 +4s => 4s - 2s = 40 - 20 => 2s = 20 => s = 20/2
=> s = 10
And c = 20 + 4s = 20 + 4(10) = 20 + 40 = 60
Step-by-step explanation:
Answer:
2 Beetle juices and 3 Potion Punch
Step-by-step explanation:
j = Beetle Juice cost $2.50
p = Potion Punch Cost $3
j + p = 5 <em>Multiply by -3</em> -3j - 3p = -15
$2.50j + $3p = $14 <em>Do not change </em>+ <em> </em><u><em> </em></u><u>2.50j -3p = 14 </u>
- .50j = -1
j = 2 Beetle Juice
Substitute into the fist equation and solve for y j + p = 5
2 + p = 5
p = 3 Potion Punch
No. Just because the angles are all less than 90 degrees, that doesn't tell us anything about the sides. The sides are all congruent ONLY if all 3 angles are 60 degrees each. If the angles all have different sizes, then so do the sides.