<span>
Experimental probability is the ratio of the number of times an event occurs to the total number of trials or times the activity is performed.</span>
Answer:
(2y - 1 -3 3x – y 2y = x - 2 answer is -3 or 56.309 or +3/2
Step-by-step explanation:
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:
22
Step-by-step explanation:
5/3=x-4/2
10=x-12
x=22