Q 53

X is a normally distributed random variable with a mean of 7 and a standard deviation of 2.5. Find the value of X for which 70.54% of the area under the distribution curve lies to the right of it. (Note: the diagram is not necessarily to scale.)
A) 6.10
B) 6.32
C) 5.65
D) 8.43

Q 54

X is a normally distributed random variable with a standard deviation of 3.50. Find the mean of X when 64.8% of the area lies to the left of 10.33. (Note: the diagram is not necessarily to scale.)
A) 7.1
B) 8.7
C) 9.0
D) 10.2

Q 55

X is a normally distributed random variable with a standard deviation of 2.00. Find the mean of X if 12.71% of the area under the distribution curve lies to the right of 8.28. (Note: the diagram is not necessarily to scale.)
A) 7.6
B) 6.6
C) 6.0
D) 5.5