Statistics test
krilee
w1_stat_test.docx1 A polling company reported that 47% of 2302 surveyed adults said that they play basketball.
Complete parts (a) through (d) below.
a. What is the exact value that is 47% of 2302?
The exact value is _________?
(Type an integer or a decimal.)
b. Could the result from part (a) be the actual number of adults who said that they play basketball? Why or why not?
A.No, the result from part (a) could not be the actual number of adults who said that they play basketball because a count of people must result in a whole number.
B.No, the result from part (a) could not be the actual number of adults who said that they play basketball because that is a very rare activity.
C.Yes, the result from part (a) could be the actual number of adults who said that they play basketball because the polling numbers are accurate.
D.Yes, the result from part (a) could be the actual number of adults who said that they play basketball because the results are statistically significant.
2. Identify the level of measurement of the data, and explain what is wrong with the given calculation.
In a set of data, internet speeds are represented as 0 for slow, 1 for medium, and 2 for fast. The average (mean) of the 587 internet speeds is 0.9 .
The data are at the( nominal ordinal,ratio,interval) level of measurement.
What is wrong with the given calculation?
A. Such data should not be used for calculations such as an average.
B.One must use a different method to take the average of such data.
C.The true average is 1.0.
D.There is nothing wrong with the given calculation.
3 Determine whether the given description corresponds to an observational study or an experiment.
In a study of 447 children with a particular disease, the subjects were asked about their diet. Does the given description correspond to an observational study or an experiment?
A.The given description corresponds to an observational study.
B.The given description corresponds to an experiment.
C.The given description does not provide enough information to answer this question.
4 Identify the type of sampling used (random, systematic, convenience, stratified, or cluster sampling) in the situation described below.
In a poll conducted by a certain research center, 737 adults were called after their telephone numbers were randomly generated by a computer, and 52 % were able to correctly identify the vice president.
Which type of sampling did the research center use?
_Systematic sampling
_Convenience sampling
_Random sampling
_Cluster sampling
_Stratified sampling
5 Determine whether the sample described below is a simple random sample.
A quality control engineer selects every 10000th hairdryer that is produced.
Does this sampling plan result in a simple random sample?
A.The sample is a simple random sample because every sample of the same size has the same chance of being selected.
B.The sample is not a simple random sample because each individual hairdryer does not have the same chance of being selected.
C.The sample is a random sample because each individual hairdryer has the same chance of being selected.
D. The sample is not a simple random sample because every sample of the same size does not have the same chance of being selected
6 An insurance institute conducted tests with crashes of new cars traveling at 6 mi/h. The total cost of the damages was found for a simple random sample of the tested cars and listed below.
Find the (a) mean, (b) median, (c) mode, and (d) midrange for the given sample data. Do the different measures of center differ very much?
$7,472 $4,908 $9,089 $6,452 $4,254
a. The mean is $____.
(Type an integer or a decimal.)
b. The median is $____.
(Type an integer or a decimal.)
c. Select the correct choice below and fill in any answer boxes in your choice.
A. The mode is $______.
(Use a comma to separate answers as needed.)
B.There is no mode.
d. The midrange is $______.
(Type an integer or a decimal.)
Do the different measures of center differ very much?
A. The median and mean differ by a very large amount.
B. The different measures of center do not differ by very large amounts.
C. There is a very large difference between the three measures.
D. Only the mean is different by a large amount.
7 Refer to the data set of times, in minutes, required for an airplane to taxi out for takeoff, listed below. Find the mean and median. How is it helpful to find the mean?
45 33 49 24 19 25 15 14 22 17 16 17 20 45 10 46 10 20 23 23 19 12 27 40 48 37 44
43 30 44 43 39 21 47 11 31 30 30 46 39 47 35 15 47 19 18 25 44
Find the mean and median of the data set using a calculator or similar data analysis technology.
The mean of the data set is _______ minutes
(Round to one decimal place as needed.)
The median of the data set is ________ minutes.
(Round to one decimal place as needed.)
How is it helpful to find the mean?
A. The mean taxi out time is important for calculating and scheduling the arrival time.
B. The mean taxi out time is important for determining the quality of the flight.
C. The mean taxi out time is important for the condition of the runway.
D. The mean taxi out time is not important.
8 Listed below are the durations (in hours) of a simple random sample of all flights of a space shuttle program. Find the range, variance, and standard deviation for the sample data. Is the lowest duration time unusual? Why or why not?
80 91 236 194 164 265 193 372 258 238 388 335 226 247 0
The range of the sample data is ______hours. (Type an integer or a decimal.)
The variance of the sample data is______(Round to one decimal place as needed.)
The standard deviation of the sample data is ________hours.
(Round to one decimal place as needed.)
Is the lowest duration time unusual? Why or why not?
A.No, because the sample is random.
B.Yes, because the lowest value in a data set is usually an outlier.
C.Yes, because it is more than two standard deviations below the mean.
D.No, because it is within two standard deviations of the mean.
9 One of the tallest living men has a height of 230 cm. One of the tallest living women is 213 cm tall. Heights of men have a mean of 176 cm and a standard deviation of 5cm. Heights of women have a mean of 157cm and a standard deviation of 6cm. Relative to the population of the same gender, who is taller? Explain.
Choose the correct answer below.
A. The woman is relatively taller because the z score for her height is less than the z score for the man's
height.
B.The man is relatively taller because the z score for his height is greater than the z score for the woman's height.
C.The woman is relatively taller because the z score for her height is greater than the z score for the man's height.
D.The man is relatively taller because the z score for his height is less than the z score for the woman's
height.
16 16 20 21 22 25 26 26 29 30 31 32 33 34 35 37 40 41 50 50 52 55 58 59 61 63 63 64 69 69 69 70 71 73 75 80
P 80 = _____________________
