Answer:
19.2
Step-by-step explanation:
You get the mean of a set of numbers by adding them and dividing the sum by how many numbers there are. In this case, you don't know what the individual 8 numbers are, but you can find out what they add up to.
Mean = (sum) / 8
17 = (sum) / 8
17 x 8 = sum
136 = sum
Now take out the numbers 9, 11, 20, which reduces the sum by 40. There are 5 numbers left and they add up to 136 - 40 = 96.
The new mean is 96 / 5 = 19.2
Answer:
The length of the circular arc is 8.64 inches
Step-by-step explanation:
Length of circular arc (L) = central angle/360° × 2πr
central angle = pie/4 = 45°, r (radius) = 11 inches
L = 45°/360° × 2 × 3.142 × 11 = 8.64 inches (to two decimal places)
Answer:
4x^2+17x+15
Step-by-step explanation:
(4x-3)(x+5)
= 4x(x+5) -3(x+5)
= 4x^2+ 20x -3x + 15
= 4x^2 + 17x + 15
The square root of 169=13 so it is rational
Answer:
The 98% confidence interval for the mean number of hours of study time per week for all students is (20.9, 25.1).
Step-by-step explanation:
Confidence interval:
Sample mean plus/minus the margin of error.
In this question:
Mean of 23.
Margin of error 2.1.
Then
23 - 2.1 = 20.9
23 + 2.1 = 25.1
The 98% confidence interval for the mean number of hours of study time per week for all students is (20.9, 25.1).
