STAT3233 Applied Statistics Quiz 3 Due Date: Monday, Oct. 06, 2008
Name: _____________________________ Score:_______/16
Please write your answers to question 1 - 11 in the table in page 3.
1. (1 pt ) If a normal distribution has mean 18 and standard deviation 4, then
A) the median is 18 and the mode is 18
B) the median is 14 and the mode is 22
C) the median is 22 and the mode is 14
D) there is insufficient information about the median and the mode.
2. ( 1 pt ) Which of the following is NOT true regarding the sample mean?
A) The distribution of the sample mean is less variable than the original distribution.
B) The mean of the sample mean could be less than the population mean.
C) As the sample size increases, the distribution of the sample mean approaches the
normal distribution, irrespective of the shape of the original distribution.
D) When the original variable is normally distributed, the distribution of the sample
mean will be normally distributed, for any sample size n.
3. (1 pt ) Find the area under the standard normal curve to the left of z = 0.94 .
A) 0.3264
B) 0.4545
C) 0.8264
D) 0.9545
4. (1 pt ) Find the area under the standard normal curve between z = -2.0 and z = 2.0 .
A) 0.4798
B) 0.4772
C) 0.9544
D) 0.9596
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