I the average score is 750 and standard deviation ( sigma ) is 50 points, then score 700 - 800 is between (750 - 1 sigma) and (750 + 1 sigma).
That is 34.1 % + 34.1 % = 68.2 % of the whole population.
2,000 · 0.682 = 1.364
We expect 1,364 students to score between 700 and 800 points.
Answer:
x=75, y = 50
Step-by-step explanation:
Solve the following system:
{x + y = 125 | (equation 1)
5 x + 8 y = 775 | (equation 2)
Swap equation 1 with equation 2:
{5 x + 8 y = 775 | (equation 1)
x + y = 125 | (equation 2)
Subtract 1/5 × (equation 1) from equation 2:
{5 x + 8 y = 775 | (equation 1)
0 x - (3 y)/5 = -30 | (equation 2)
Multiply equation 2 by -5/3:
{5 x + 8 y = 775 | (equation 1)
0 x+y = 50 | (equation 2)
Subtract 8 × (equation 2) from equation 1:
{5 x+0 y = 375 | (equation 1)
0 x+y = 50 | (equation 2)
Divide equation 1 by 5:
{x+0 y = 75 | (equation 1)
0 x+y = 50 | (equation 2)
Collect results:
Answer: {x = 75
, y = 50
The prompt says that the value at n is equal to 2 times the previous value.
-1, -2, -4, -8, -16, -32