Answer:
Mean is 81%
standard deviation is approximately 4.2%
Step-by-step explanation:
Since the number of boys equals the number of girls, but it is not given, we name it "N". and proceed to calculate the mean as:
Mean = (0.78 * N + 0.84 * N) /(2 N)
using that the total number of students must be N boys + N girls = 2 N
Then the Mean becomes: N *(0.78 + 0.84) /(2 N) = (0.78 + 0.84) / 2 = 1.62 / 2 = 0.81
So the mean is 81%
Now, standard deviation will be calculated by first adding the squares of the deviations: (X-0.81)^2 for the N boys and for the N girls, and then finding the square root of this and finally dividing by the square root of N. That is:
Now finding the square root of this value, and finally dividing it by the square root of N:
which in percent form is: approximately 4.2%
Answer:
I think it is 4.52 × 10^-4
Answer:
The expression to this question is "".
Step-by-step explanation:
Answer:
Therefore, a ratio of 8/6 is an equivalent ratio of 4/3: in that particular ratio calculation, you should just multiply 4, as well as 3, by 2.
Step-by-step explanation:
I hope this helps! :D
Answer: x ≤ 1
reason:
first, multiply 4x and 4 by -2/3, which leaves you with the equation 2x ≤ -8/3x + 8/3
then, you add 8/3x to both sides, making it 4 2/3x ≤ 8/3
divide both sides by 4 2/3 and you get x ≤ 1