Answer:
here is the correct answer
Answer:
im pretty sure its A
Step-by-step explanation:
Hope this helped!
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:
180, 180, 148, 180, 148
Step-by-step explanation:
The two rules in play here are ...
- the sum of interior angles of a triangle is 180°
- the angles of a linear pair are supplementary (they total 180°)
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The first of these rules answers the first two questions:
- interior angles total 180°
- angles 1, 3, 4 total 180°
We can subtract the measure of angle 1 from both sides of the previous equation to find the sum of the remaining two angles.
- angles 3 and 4 total 148°
The second rule answers the next question:
- angles 1 and 2 total 180°
As before, subtracting the value of angle 1 from both sides of the equation gives ...
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<em>Additional comment</em>
Of course, the subtraction property of equality comes into play, also. For some unknown, X, you have (in both cases) ...
X + 32° = 180°
X +32° -32° = 180° -32° . . . . . . subtraction property of equality
X = 148° . . . . . . . . simplify
In the first case, X is the sum of angles 3 and 4. In the second case, X is angle 2 only.
Answer:
110
Step-by-step explanation:
Let x = rate #1 and then 155-x=rate #2.
15x + 5(155-x) = 1225
15x - 5x + 775 - 1225
10x = 450
x = 45, second rate is 110
