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:
30
Step-by-step explanation:
Work backwards:
- 6 is 3/5 of a number, and that number is 10
- 10 is 1/3 of a number, and that number is 30
Check your work:
- 2/3 of 30=20 toy to Sarah
- 30-20=10 toys left
- 2/5 of 10=4 toys to Ryan
- 10-4=6 toys left
Answer:
following. Write your answer as fraction in lowest terms. (f + g)(-5) = d. [4 pt.] ...
10 pages·
Step-by-step explanation:
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