Download - River Mill Academy

Name _______________________
Statistics test, AFM
Assume Normal Distribution unless otherwise stated!
Part 1: Circle the best answer. NOTA=none of the above (3 pts each)
For questions 1-4, use the following:
___________________________________________________________
3
|
4
4
4
|
5
6
5
|
5
9
5
1) Mean
a) 7
b) 44
c) 51.3
d) 308
b) 34
c) 45
d) none
b) 40
c) 45
d) 55
c) histogram
d) number tree
2) Mode?
a) 5
3) Median?
a) 35
4) The above graphic is called…?
a) stem-and-leave plot b) box-and-whisker plot
5) The linear regression statistic that tells what percent of the data is explained by the model is:
a) a
b) b
c) r
d) r2
6) The standard deviation of the following sample data set is…?
45
a) 15.6
67
20
30
b) 17.7
40
c) 40.4
d) 313.29
7) If the average height of a RMA high school student is 65 inches with a standard deviation of 4 inches,
99.7% of all high school students are between_________ inches.
a) 65-69
b)57 – 73
c) 53 – 77
d) NOTA
8) On the test with an 85 average with a standard deviation of 4, what percent of the students received
between a 78 and a 88?
a) 4.01
b) 73.33
c) 77.34
d) 100
For 9-11, use the following statistics from the linreg to answer the questions
A= 40
b=2.5
r2=.0144
r=-.12
9) A linear model is/is not appropriate because:
a) b is greater than 1
b) r is almost than 0
c) r2 is almost 0
d) p<.05
c) y=.002 + -.12
d) NOTA
c) 2.5%
d) 12%
10) What is the equation of the regression line?
a) y=40+2.5 x
b) y=2.5 + .002x
11) What percent of the data is explained by the model?
a) .2%
c) 1.4%
12) All of the following are good practices for surveys EXCEPT:
a) Providing anonymity
b) Randomizing the question order
c) Ask questions in the most contentious way possible
d) Ask a large number of people
13) If a data set has a mean of 30 and a standard deviation of 8, what is the z-score of 26?
a) -2.5
b)2.5
c) 22
d) NOTA
14) What is the standard deviation of the following sample?
40
a) 22.8
50
b) 25.5
70
90
c) 70
100
d) 650.25
15) If a standardized test has a mean of 145 and a standard deviation of 10, what is the percentile of a
person who scores 163?
a)3.6
b) 46.4
c) 96.4
d) NOTA
16) What percent of the class is between 67 inches and 72 inches tall if the class average is 66 inches
with a standard deviation of 5?
a) 6.2
b) 30.6
c) 42.1
d) NOTA
17) What is the z-score of 40 if the mean is 25 and the standard deviation is 10?
a) -1.5
b) 1.3
c) 1.5
d) NOTA
18) If the class average was an 80 with a standard deviation of 5, 99% of the class scored between:
a) 75 and 85
b) 70 and 90
c) 65 and 95
d) NOTA
19) If the average income is 70,000 with a standard deviation of 15,000, what percent of those jobs
earn more than 80,000?
a) 25.2
b)50
c) 74.8
d) NOTA
20) If the average insect is 13 mm in length with a standard deviation of 4 mm, 68% of the insects are
between:
a) 9 and 17
b) 5 and 21
c) 48 and 56
d) NOTA
Part 2: Short answer (5 pts each)
1) If I ask the class to raise their hands if they feel that the principal is doing a good job to find out what
the student body’s opinion is of the administration, why might my data be faulty?
2) If the following is the data for my linear regression:
X
y
3
27
4
25
5
19
13
3
27
1
34
.6
a) Is a linear model appropriate? Why/why not?
b) Are we 95% confident that there Is a relationship between x and y? Why/why not?
c) If our model is accurate, a one unite increase in x creates how much of an increase in y?
3) If the test scores are normally distributed with a standard deviation of 6 and a mean of 82, what
percent of the class scored between 80 and 90?
4) Construct a box-and-whisker plot of the following data. Be sure to label all important points on the
graph.
1
6
8
10
12
12
15
5) I want to give out an award to the top 15% of the school based on gpa. If the high school average gpa
at RMA is 3.4 with a standard deviation of .07, I will award students who make at least what gpa?
6) Name one type of faulty sampling technique, and discuss why it is leads to
unreasonable/invalid/biased data.
7) Find the equation of the line that goes through the points (4,-2) and (10,7)
8) Find the slope of the line 8x-4y=12