In: Statistics and Probability
A statistic center compiles data on the length of stay by patients in short-term hospitals. A random sample of 2121 patients yielded the data on length of stay, in days, shown below. Complete parts (a) through (e) below. 24 4 5 18 4 14 55 23 23 7 10 5 9 1 20 25 5 18 19 14 2324 4 5 18 4 14 55 23 23 7 10 5 9 1 20 25 5 18 19 14 23.
a.
Obtain and interpret the quartiles.
Upper Q 1Q1 |
equals= |
nothing |
Upper Q 2Q2 |
equals= |
nothing |
Upper Q 3Q3 |
equals= |
nothing |
(Type integers or decimals.)
Interpret the quartiles. Choose the correct answer below.
A.The quartiles suggest that 33% of the patients stayed less than
55
days, 33% stayed between
55
and
2323
days, and 33% stayed more than
2323
days.
B.The quartiles suggest that the average length of stay is
1414
days.
C.The quartiles suggest that all the patients stayed between
55
and
2323
days.
D.The quartiles suggest that 25% of the patients stayed less than
55
days, 25% stayed between
55
and
1414
days, 25% stayed between
1414
and
2323
days, and 25% stayed more than
2323
days.
b.
Determine and interpret the interquartile range (IQR).
IQRequals=nothing
(Simplify your answer. Type an integer or decimal.)
Interpret the IQR. Choose the correct answer below.
A.The data span roughly
1818
days.
B.The length of stay in the middle 50% of patients spans roughly
1818
days.
C.The approximate difference between each quartile is
1818.
D.The average of the first quartile and the third quartile is
1818.
c.
Find and interpret the five-number summary.
nothing
nothing
nothing
nothing
nothing
(Type integers or decimals. Use ascending order.)
Interpret the five-number summary. Choose the correct answer below.
A.
The middle 50% has the greatest variation in the data set. The first and fourth quarters have the same variation.
B.The fourth quarter has the greatest variation. The
middle 50 %middle 50%
has the next largest variation and the
first quarterfirst quarter
has the least variation.
C.
There aren't as many patients in the fourth quarter as there are in the first quarter.
D.
The first quarter has the most patients recorded. The fourth quarter has the least amount of patients recorded.
d.
Identify potential outliers, if any. Choose the correct answer below and, if necessary, fill in the answer box to complete your choice.
A.The potential outlier(s) is(are)
nothing.
(Type an integer or a decimal. Use a comma to separate answers as needed.)
B.
There are no potential outliers.
e.
Construct and interpret a boxplot. Choose the correct boxplot below.
A.
0102030405060
A boxplot has a horizontal axis labeled from 0 to 60 in increments of 10. There are vertical line segments drawn at the following values: 1, 5, 14, 23, 25. A box encloses the vertical line segments at 5, 14, and 23, and horizontal line segments extend outward from both sides of the box to the vertical line segments at 1 and 25. There is a plotted point at 55. All values are approximate.
B.
0102030405060
A boxplot has a horizontal axis labeled from 0 to 60 in increments of 10. There are vertical line segments drawn at the following values: 6, 10, 20, 29, 31. A box encloses the vertical line segments at 10, 20, and 29, and horizontal line segments extend outward from both sides of the box to the vertical line segments at 6 and 31. There are plotted points at 45 and 55. All values are approximate.
C.
0102030405060
A boxplot has a horizontal axis labeled from 0 to 60 in increments of 10. There are vertical line segments drawn at the following values: 2, 8, 21, 35, 38. A box encloses the vertical line segments at 8, 21, and 35, and horizontal line segments extend outward from both sides of the box to the vertical line segments at 2 and 38. All values are approximate.
Interpret the boxplot. Choose the correct answer below.
A.Most stays were approximately
2121
days. The longest stay was
37.537.5
and the shortest stay was
1.51.5.
B.The potential outlier is relatively close to the other data points. Most stays fall with the first quarter of the boxplot, between
7.57.5
and
2121.
C.The potential outlying observation falls far from the rest of the data. The other stays vary from
11
to
2525
days. The majority of the stays were between
55
and
2323
days.
D.The two potential outlying observations fall far from the rest of the data. The other observations vary from
6.056.05
to
31.2531.25
days. The majority of the stays were between
10.2510.25
and
29.1529.15
days.
Answer: A statistic center compiles data on the length of stay by patients in short-term hospitals. A random sample of 2121 patients yielded the data on length of stay, in days, shown below.
24 4 5 18 4 14 55 23 23 7 10 5 9 1 20 25 5 18 19 14 23.
Solution:
To find the quartile first arrange the data in ascending order.
1,4,4,5,5,5,7,9,10,14,14,
18,18,19,20,23,23,23,24,25,55
a) Obtain and interpret the quartiles.
For Q1:
median of lower half
n = 10
n+1/2 = (10+1)/2 =11/2 = 5.5
Q1 = (5th + 6th value in ascending order) /2 = (5+5)/2 = 5
Q2 = 11th value in ascending order = 14
median of upper half
n+1/2 = (10+1)/2 = 11/2 = 5.5
Q3 = (5th and 6th value in ascending order) /2 = (23+23)/2 = 23
Therefore,
Q1 = 5
Q2 = 14
Q3 = 23
The option D is correct answer.
D.The quartiles suggest that 25% of the patients stayed less than 5 days, 25% stayed between 5 and 14 days, 25% stayed between 14 and 23 days, and 25% stayed more than 23 days.
b) Determine and interpret the interquartile range (IQR).
IQR = Q3- Q1
IQR = 23 - 5
IQR =18
Answer A. The data span roughly 18 days.
c) Find and interpret the five-number summary.
Five number summary:
Minimum, Q1, Q2, Q3, Maximum
1, 5, 14, 23, 55
The option B. is correct answer.
B.The fourth quarter has the greatest variation. The middle 50 % has the next largest variation and the first quarterfirst quarter has the least variation.
d) Identify potential outliers, if any.
The potential outlier is 55.
e) Construct and interpret a boxplot.
The option C. is correct answer.
C. The potential outlying observation falls far from the rest of the data. The other stays vary from 1 to 25 days, the majority of the stays were between 5 and 23 days.