Answer:
The probability that the average of the scores of all 400 students exceeds 19.0 is larger than the probability that a single student has a score exceeding 19.0
Step-by-step explanation:
Xi~N(18.6, 6.0), n=400, Yi~Ber(p); Z~N(0, 1);
P(Xi≥19.0)=0.473
p=0.473
Yi~Ber(0.473)
Based on the Central Limit Theorem:
Then:
Based on the Central Limit Theorem:
Then:
the probability that the average of the scores of all 400 students exceeds 19.0 is larger than the probability that a single student has a score exceeding 19.0
Answer:
B
Step-by-step explanation:
let's see, I'd the point on the line/boundary ?
for this we use the equality part (and use the coordinates of the point as x and y) :
-8 = 2×2² - 5×2 - 6 = 8 - 10 - 6 = -2 - 6 = -8
correct.
this proves that the point is on the line defined by the equation.
and that means it is on the boundary of the inequality.
because that inequality contains the boundary in the solution region (hence the >= relation instead of just >), we cannot use that point to determine which side of the boundary (incl. the boundary line, but still) is the solution region.
