Complete the following:
Q1. The mean amount of gasoline and services charged by Key Refining Company credit customers is $70 per month. The distribution of amounts spent is approximately normal with a standard deviation of $10. What is the probability of selecting a credit card customer at random and finding the customer charged between $70 and $83?
A) 0.1962
B) 0.4032
C) 0.3413
D) 0.4750
Q2. The upper and lower limits of a uniform probability distribution are:
positive and negative infinity.
plus and minus three standard deviations.
0 and 1.
the maximum and minimum values of the random variable.
Q3. The employees of Cartwright Manufacturing are awarded efficiency ratings. The distribution of the ratings approximates a normal distribution. The mean is 400, the standard deviation 50. What is the area under the normal curve between 400 and 482?
A) 0.5000
B) 0.4495
C) 0.3413
D) 0.4750