Name ___ ______________________________
Exam 1
–
Part 1: Chapters 15
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Math &146
–
Spring 2010
Instructions: Show work for each question.
Partial credit will be awarded based on work shown. This includes showing what was entered into the
calculator and sketching the Normal distributions.
To clarify the final solution, box it.
There is a 120 minute time limit. A graphing calculator
must be used.
Each problem is worth 4 points.
There are 4 extra credit points possible.
Assume all rounding to be at 4 decimal places
Problems 16
[4 points each]
The lengths of pregnancies in a small rural
village are Normally distributed with a mean of 265 days and a standard
deviation of 13 days.
1.
What proportion of pregnancies are longer than 275 days?
2.
10% of pregnancies last longer than how many days?
3.
What proportion of pregnancies are longer than 250 days and
shorter than 280?
4.
Using the 689599.7 Rule, what pregnancies lengths make up the
middle 95%?
5.
Is this distribution considered a standard Normal distribution
?
If not,
what mean and standard deviation would make it a standard Normal
distribution?
6.
Suppose Ana
’s pregnancy lasted 270 days.
a.
What is her
z
score?
b.
If another woman in the hospital gave birth on the same day as
she did with a
z
score of 0, who conceived first?
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View Full DocumentExam 1
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Math 146
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Spring
’10
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Page 2
Problems 78
A sample was taken of the verbal SAT scores of applicants
to a California State College. The following is a boxplot of the scores.
7.
What is the approximate scores for the middle 50% of the verbal SAT
scores above?
8.
State three other useful facts about the boxplot above.
In other
words, list three pieces of information you can gather from the plot.
Problems 711
[5 points each]
In a Statistics class with 136 students, the
professor records how much money each student has in his or her
possession during the first class of the semester. The histogram below is
of the data collected.
9.
From the histogram above, in what interval(s) can the median be
found?
10.
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 Spanish, Normal Distribution, Standard Deviation, burnt grasslands decreases

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