1. Identify the variable in the information here.
The archeological site of Tara is more than 4000 years old. Tradition states that Tara was the seat of the high kings of Ireland. Because of its archeological importance, Tara has received extensive study (Reference: Tara: An Archeological survey by Conor Newman, Royal Irish Academy, Dublin). Suppose an archeologist wants to estimate the density of ferromagnetic artifacts in the Tara region. For this purpose, a random sample of 55 plots, each of size 100 square meters, is used. The number of ferromagnetic artifacts for each plot is determined.
(Points: 4)
number of plots
size of the plots
the density of artifacts
number of ferromagnetic artifacts per 100 square meters
number of plots as well as size of the plots
2. Use the list of random numbers given below to simulate the outcomes of tossing a quarter 11 times. Assume that the quarter is balanced (i.e., fair) and an even digit is assigned to the outcome heads (H) and an odd digit to the outcome tails (T).
9 1 9 7 2 3 9 8 0 0 4
(Points: 4)
T T T T H T H H H H H
T T T T H T T H H H H
T T T T H H T H H H H
T T T T H T T H H H T
T T T T H T T H H T H
3. Finish times (to the nearest hour) for 59 dogsled teams are shown below. Draw a histogram. Use five classes. 261
269
236
244
280
296
284
297
290
290
247
256
338
360
341
333
261
267
287
296
313
311
309
309
299
303
277
283
304
305
286
290
286
287
297
299
332
330
309
326
309
326
285
291
295
298
306
315
310
318
318
320
333
321
323
324
327
239
358
The frequency table for the above data is given below.
Class Limits
Boundaries
Midpoint
Freq.
Relative Freq.
Cumulative Freq.
236 260
235.5 260.5
248
5
0.08
5
261 285
260.5 285.5
273
9
0.15
14
286 310
285.5 310.5
298
25
0.42
39
311 335
310.5 335.5
323
16
0.27
55
336 360
335.5 360.5
348
4
0.07
59
(Points: 4)
4. Finish times (to the nearest hour) for 57 dogsled teams are shown below. Use five classes. Categorize the basic distribution shape as uniform, mound-shaped symmetric, bimodal, skewed left, or skewed right.
The relative frequency histogram of the above data is given below.
(Points: 4)
approximately skewed left
approximately bimodal
approximately uniform or rectangular
approximately mound-shaped symmetric
approximately skewed right
5. Pyramid Lake, Nevada, is described as the pride of the Paiute Indian Nation. It is a beautiful desert lake famous for very large trout. The elevation of the lake surface (feet above sea level) varies according to the annual flow of the Truckee River from Lake Tahoe. Assume that the U.S. Geological Survey provided the following data:
Year
1986
1987
1988
1989
1990
1991
1992
1993
Elevation
3812
3815
3817
3803
3798
3808
3795
3797
Year
1994
1995
1996
1997
1998
1999
2000
Elevation
3811
3797
3802
3811
3819
3820
3812
Make a time series graph.
(Points: 4)
6. Use the data given in the following table to make a stem-and-leaf display for milligrams of nicotine per cigarette smoked. In th.
1. Identify the variable in the information here.The archeological.docx
1. 1. Identify the variable in the information here.
The archeological site of Tara is more than 4000 years old.
Tradition states that Tara was the seat of the high kings of
Ireland. Because of its archeological importance, Tara has
received extensive study (Reference: Tara: An Archeological
survey by Conor Newman, Royal Irish Academy, Dublin).
Suppose an archeologist wants to estimate the density of
ferromagnetic artifacts in the Tara region. For this purpose, a
random sample of 55 plots, each of size 100 square meters, is
used. The number of ferromagnetic artifacts for each plot is
determined.
(Points: 4)
number of plots
size of the plots
the density of artifacts
number of ferromagnetic artifacts per 100 square meters
number of plots as well as size of the plots
2. Use the list of random numbers given below to simulate the
outcomes of tossing a quarter 11 times. Assume that the quarter
is balanced (i.e., fair) and an even digit is assigned to the
outcome heads (H) and an odd digit to the outcome tails (T).
9 1 9 7 2 3 9 8 0 0 4
(Points: 4)
T T T T H T H H H H H
T T T T H T T H H H H
T T T T H H T H H H H
T T T T H T T H H H T
T T T T H T T H H T H
3. Finish times (to the nearest hour) for 59 dogsled teams are
5. 59
(Points: 4)
4. Finish times (to the nearest hour) for 57 dogsled teams are
shown below. Use five classes. Categorize the basic distribution
shape as uniform, mound-shaped symmetric, bimodal, skewed
left, or skewed right.
The relative frequency histogram of the above data is given
below.
(Points: 4)
approximately skewed left
approximately bimodal
approximately uniform or rectangular
approximately mound-shaped symmetric
approximately skewed right
5. Pyramid Lake, Nevada, is described as the pride of the Paiute
Indian Nation. It is a beautiful desert lake famous for very large
trout. The elevation of the lake surface (feet above sea level)
varies according to the annual flow of the Truckee River from
Lake Tahoe. Assume that the U.S. Geological Survey provided
the following data:
Year
7. 3812
Make a time series graph.
(Points: 4)
6. Use the data given in the following table to make a stem-and-
leaf display for milligrams of nicotine per cigarette smoked. In
this case, truncate the measurements at the tenths position and
use two lines per stem.
Brand
Brand
Alpine
0.82
Multifilter
0.78
Benson & Hedges
1.07
Newport Lights
0.69
Bull Durham
12. 7. In your biology class, your final grade is based on several
things: a lab score, score on two major tests, and your score on
the final exam. There are 100 points available for each score.
However, the lab score is worth 25% of your total grade, each
major test is worth 22.5%, and the final exam is worth 30%.
Compute the weighted average for the following scores: 92 on
the lab, 83 on the first major test, 94 on the second major test,
and 84 on the final exam. Round your answer to the nearest
hundredth. (Points: 4)
86.02
88.42
88.02
85.55
90.42
8. Suppose automobile insurance companies gave annual
premiums for top-rated companies in several states. The figure
below shows box plots for the annual premium for urban
customers in three states.
Which state has the smallest range of premiums?
(Points: 4)
California has the smallest range of premiums.
Pennsylvania has the smallest range of premiums.
Texas has the smallest range of premiums.
Texas as well as Pennsylvania have the smallest ranges.
Texas has the largest range of premiums.
9. Is the magnitude of an earthquake related to the depth below
13. the surface at which the quake occurs? Let x be the magnitude
of an earthquake (on the Richter scale), and let y be the depth
(in kilometers) of the quake below the surface at the epicenter.
Suppose a random sample of earthquakes gave the following
information.
As x increases, does the value of r imply that y should tend to
increase, decrease, or remain the same? Explain.
(Points: 4)
Since r is zero, as x increases, y decreases.
Since r is negative, as x increases, y remains the same.
Since r is negative, as x increases, y decreases.
Since r is positive, as x increases, y increases.
Since r is positive, as x increases, y remains the same.
10. It is thought that prehistoric Indians did not take their best
tools, pottery, and household items when they visited higher
elevations for their summer camps. It is hypothesized that
archaeological sites tend to lose their cultural identity and
specific cultural affiliation as the elevation of the site increases.
Let x be the elevation (in thousands of feet) for an
archaeological site in the southwestern United States. Let y be
the percentage of unidentified artifacts (no specific cultural
affiliation) at a given elevation. Suppose that the following data
were obtained for a collection of archaeological sites in New
Mexico:
Given that:
what percentage of the variation in y cannot be explained by the
14. corresponding variation in x and the least-squares line?
(Points: 4)
2.1%
7.2%
26.9%
73.1%
85.5%
11. John runs a computer software store. He counted 124 people
who walked by his store in a day, 55 of whom came into the
store. Of the 55, only 21 bought something in the store.
Estimate the probability that a person who walks by the store
will come in and buy something. Round your answer to the
nearest hundredth. (Points: 4)
0.17
0.38
0.12
0.61
0.25
12. You draw two cards from a standard deck of 52 cards and
replace the first one before drawing the second. Find the
probability of drawing a 9 and a king in either order. Round
your answer to the nearest thousandth. (Points: 4)
0.078
0.012
0.037
0.311
0.024
13. There are three nursing positions to be filled at Lilly
Hospital. Position 1 is the day nursing supervisor, position 2 is
15. the night nursing supervisor; and position 3 is the nursing
coordinator position. There are 19 candidates qualified for 3 of
the positions. Determine the number of different ways that 3
positions can be filled by these applicants. (Points: 4)
5814
969
19
57
437
14. Jim has a 5-year-old car in reasonably good condition. He
wants to take out a $30,000 term (that is, accident benefit) car
insurance policy until the car is 10 years old. Assume that the
probability of a car having an accident in the year in which it is
x years old is as follows:
x = age
5
6
7
8
9
P (accident)
0.01191
0.01292
0.01396
0.01503
0.01613
Jim is applying to a car insurance company for his car insurance
policy. If the car insurance company wants to make a profit of
$900 above the expected total losses, how much should it
charge for the policy? Round your answer to the nearest dollar.
16. (Points: 4)
$2997
$2999
$3001
$2994
$2992
15. Suppose that about 20% of those called will find an excuse
(work, poor health, travel out of town, etc.) to avoid jury duty.
If 14 people are called for jury duty, what is the probability that
all 14 will be available to serve on the jury? Round your answer
to three decimal places. (Points: 4)
0.035
0.044
0.000
0.055
1.000
16. At a certain excavation site, archaeological studies have
used the method of tree-ring dating in an effort to determine
when people lived in there. Wood from several excavations gave
a mean of (year) 1332 with a standard deviation of 24 years.
The distribution of dates was more or less mound-shaped and
symmetrical about the mean. Use the empirical rule to estimate
a range of years centered about the mean in which about 99.7%
of the data (tree-ring dates) will be found. (Points: 4)
from 1284 to 1356
from 1284 to 1332
from 1332 to 1356
from 1260 to 1284
from 1260 to 1404
17. 17. Let z be a random variable with a standard normal
distribution. Find the indicated probability below.
(Points: 4)
0.029
0.953
0.982
0.471
0.579
18. Find z such that 20.3% of the standard normal curve lies to
the right of z. (Points: 4)
0.831
0.533
-0.533
-0.257
0.257
19. How do frequency tables, relative frequencies, and
histograms showing relative frequencies help us understand
sampling distributions? (Points: 4)
They help us to measure or estimate of the likelihood of a
certain statistic falling within the class bounds.
They help us visualize the probability distribution through
tables and graphs that approximately represent the random
sampling distribution.
They help us visualize the probability distribution through
tables and graphs that approximately represent the population
distribution.
They help us visualize the sampling distribution through tables
and graphs that approximately represent the sampling
distribution.
They help us visualize the statistic through tables and graphs
18. that approximately represent the sampling distribution.
20. Assume that about 45% of all U.S. adults try to pad their
insurance claims. Suppose that you are the director of an
insurance adjustment office. Your office has just received 110
insurance claims to be processed in the next few days. What is
the probability that fewer than 45 of the claims have been
padded? (Points: 4)
0.778
0.831
0.194
0.806
0.169
21. Total plasma volume is important in determining the
required plasma component in blood replacement theory for a
person undergoing surgery. Plasma volume is influenced by the
overall health and physical activity of an individual. Suppose
that sample of 50 male firefighters are tested and that they have
a plasma volume sample mean of ml/kg (milliliters of plasma
per kilogram body weight). Assume that ml/kg for the
distribution of blood plasma. Find the 95% confidence interval
of the population mean blood plasma volume in male
firefighters. Round your answer to two decimal places. (Points:
4)
37.47 ml/kg to 39.53 ml/kg
36.87 ml/kg to 35.87 ml/kg
36.37 ml/kg to 40.63 ml/kg
38.20 ml/kg to 38.80 ml/kg
38.13 ml/kg to 38.87 ml/kg
22. A random sample of medical files is used to estimate the
proportion p of all people who have blood type B. If you have
19. no preliminary estimate for p, how many medical files should
you include in a random sample in order to be 85% sure that the
point estimate will be within a distance of 0.1 from p? (Points:
4)
208
8
4
104
52
23. Suppose that the mean time for a certain car to go from 0 to
60 miles per hour was 7.6 seconds. Suppose that you want to
test the claim that the average time to accelerate from 0 to 60
miles per hour is different from 7.6 seconds. What would you
use for the alternative hypothesis? (Points: 4)
seconds
seconds
seconds
seconds
seconds
24. Let x be a random variable representing dividend yield of
Australian bank stocks. We may assume that x has a normal
distribution with A random sample of 17 Australian bank stocks
has a sample mean of For the entire Australian stock market, the
mean dividend yield is Do these data indicate that the dividend
yield of all Australian bank stocks is higher than 6.7%? Use Are
the data statistically significant at the given level of
significance? Based on your answers, will you reject or fail to
reject the null hypothesis? (Points: 4)
The P-value is less than the level of significance and so the data
are not statistically significant. Thus, we fail to reject the null
hypothesis.
The P-value is less than the level of significance and so the data
20. are statistically significant. Thus, we fail to reject the null
hypothesis.
The P-value is greater than the level of significance and so the
data are statistically significant. Thus, we fail to reject the null
hypothesis.
The P-value is greater than the level of significance and so the
data are not statistically significant. Thus, we fail to reject the
null hypothesis.
The P-value is less than the level of significance and so the data
are statistically significant. Thus, we reject the null hypothesis.
25. A professional employee in a large corporation receives an
average of e-mails per day. Most of these e-mails are from other
employees in the company. Because of the large number of e-
mails, employees find themselves distracted and are unable to
concentrate when they return to their tasks. In an effort to
reduce distraction caused by such interruptions, one company
established a priority list that all employees were to use before
sending an e-mail. One month after the new priority list was put
into place, a random sample of 38 employees showed that they
were receiving an average of e-mails per day. The computer
server through which the e-mails are routed showed that Has the
new policy had any effect. Use a 1% level of significance to test
the claim that there has been a change (either way) in the
average number of e-mails received per day per employee. What
are the critical values? (Points: 4)
2.58
-2.33 and 2.33
-0.842 and 0.842
1.28
-2.58 and 2.58