A standardized exam\'s scores are normally distributed. In a recent year, the me
ID: 3176492 • Letter: A
Question
A standardized exam's scores are normally distributed. In a recent year, the mean test score was 1467 and the standard deviation was 312. The test scores of four students selected at random are 1870,1230,2140,and 1350.
Find the z-scores that correspond to each value and determine whether any of the values are unusual.
1)The z-score for 1870 is____ (Round to two decimal places as needed.)
2)The z-score for 1230 is ____
3)The z-score for 2140 ___ (Round to two decimal places as needed.)
4) The z-score for 1350 is ____ (Round to two decimal places as needed.)
Which values, if any, are unusual? Select the correct choice below and, if necessary, fill in the answer box within your choice.
A. The unusual value(s) is/are ___ (Use a comma to separate answers as needed.)
B. None of the values are unusual.
Explanation / Answer
answer
mean=1467
standard deviation=312
1)z-score for 1870 is= 1870-1467/312
=1.29
2)z-score for 1230 is=1230-1467/312
=-0.75
3)z-score for 2140 is=2140-1467/312
=2.15
4)z-score for 1350 is=1350-1467/312
=-2.61
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