Answer:
a) 11.7% of students study for more than 10 hours per week.
b) 35.6% of student spends between 7 and 9 hours studying.
c) 1.6% of students spend fewer than 3 hours studying.
d) 5% of all A students spend studying 4.0455 or less hours during a week.
Step-by-step explanation:
We are given the following information in the question:
Mean, μ = 7.5 hours
Standard Deviation, σ = 2.1 hours
We are given that the distribution of amount of time is a bell shaped distribution that is a normal distribution.
Formula:
a) P(students study for more than 10 hours per week)
P(x > 10)
Calculation the value from standard normal z table, we have,
b) P(student spends between 7 and 9 hours studying.)
c) P(students spend fewer than 3 hours studying)
Calculating the value from the standard normal table we have,
d) P(X < x) = 0.05
We have to find the value of x such that the probability is 0.035
Calculation the value from standard normal z table, we have,
5% of all A students spend studying 4.0455 or less hours during a week.
