Answer:
answer is no solution (filler)
Let
be the random variable for the number of marks a given student receives on the exam.
10% of students obtain more than 75 marks, so

where
follows a standard normal distribution. The critical value for an upper-tail probability of 10% is

where
denotes the CDF of
, and
denotes the inverse CDF. We have

Similarly, because 20% of students obtain less than 40 marks, we have

so that

Then
are such that


and we find

Answer:
x=−7/5and y=−6/5
Step-by-step explanation:
Step: Substitute−2x−4foryiny=3x+3:
y=3x+3
−2x−4=3x+3
−2x−4+−3x=3x+3+−3x(Add -3x to both sides)
−5x−4=3
−5x−4+4=3+4(Add 4 to both sides)
−5x=7
−5x
−5
=
7
−5
(Divide both sides by -5)
x=−7/5
Answer:
I
Step-by-step explanation:
Because independent sample t-tests compare two completely different groups in a sample, which is what the researcher is attempting to do.
They should receive 72 each 362 divided by 5 (number people)