Answer:
Its a and b if you can click them both but its not c
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:
No
Step-by-step explanation:
You cant have 2 y values
Answer:
I would say parallelogram. So the rectangle still fits but more shapes can be applied.
Answer: 0.38
Step-by-step explanation:
Since the variable x is represented by a standard normal distribution, the probability of x > 0.3 will be calculated thus:
P(x > 0.3)
Then, we will use a standard normal table
P(z > 0.3)
= 1 - p(z < 0.3)
= 1 - 0.62
= 0.38
Therefore, p(x > 0.3) = 0.38
The probability of x > 0.3 is 0.38.