|
|
GMAT Club Daily Prep
Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.
Customized
for You
Track
Your Progress
Practice
Pays
Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.
20 Feb 2023, 02:30
Kudos
Bookmarks
D
Be sure to select an answer first to save it in the Error Log before revealing the correct answer (OA)!
Difficulty:
45%
(medium)
Question Stats:
60% (01:16) correct
40%
(01:31)
wrong
based on 143
sessions
History
Date
Time
Result
Not Attempted Yet
What is the standard deviation of set X, containing consecutive odd integers?
(1) Set consists of 10 elements
(2) The range of set is 18
700-Level Question!!!
(1) Set consists of 10 elements
(2) The range of set is 18
700-Level Question!!!
20 Feb 2023, 11:35
Kudos
Bookmarks
Few important points on Standard Deviation
1) Standard deviation is simply a measure of how far on average each term in a set is from the mean.
2) If we add or subtract a constant to each term in a set: Mean will increase or decrease by the same constant. But, SD will not change.
3) If we increase or decrease each term in a set by the same percent (multiply all terms by the constant): Mean will increase or decrease by the same percent. SD will increase or decrease by the same percent.
Now with this information lets solve the given question.
What is the standard deviation of set X, containing consecutive odd integers?
(1) Set consists of 10 elements
In a consecutive set, we know that, mean = median and since we know how far each term is from the mean we can definitely get the SD value. Statement 1 is Sufficient
(2) The range of set is 18: Range is the difference of last term and first term.
It implies that we have 10 consecutive odd integers : {1,3,5,.....19} or {9,11,13, .... 27}
So we have the same information as in statement 1.
So statement 2 is also sufficient
Answer D
1) Standard deviation is simply a measure of how far on average each term in a set is from the mean.
2) If we add or subtract a constant to each term in a set: Mean will increase or decrease by the same constant. But, SD will not change.
3) If we increase or decrease each term in a set by the same percent (multiply all terms by the constant): Mean will increase or decrease by the same percent. SD will increase or decrease by the same percent.
Now with this information lets solve the given question.
What is the standard deviation of set X, containing consecutive odd integers?
(1) Set consists of 10 elements
In a consecutive set, we know that, mean = median and since we know how far each term is from the mean we can definitely get the SD value. Statement 1 is Sufficient
(2) The range of set is 18: Range is the difference of last term and first term.
It implies that we have 10 consecutive odd integers : {1,3,5,.....19} or {9,11,13, .... 27}
So we have the same information as in statement 1.
So statement 2 is also sufficient
Answer D
21 Feb 2023, 03:17
Kudos
Bookmarks
sivakumarm786
To solve this problem, we can use the following property: If we add (or subtract) a constant to each term in a set, the set's standard deviation remains the same.
Both statements in the problem tell us that the set consists of 10 consecutive odd integers.
All sets of 10 consecutive odd integers have the same standard deviation. This is because any set of 10 consecutive odd integers can be obtained by adding a constant to another set of 10 consecutive odd integers. For example, the set {1, 3, 5, ..., 19} consists of 10 consecutive odd integers, and we can obtain it by adding 4 to each term of the set {-3, -1, 1, ..., 15}. So, we can calculate the standard deviation of any set of 10 consecutive odd integers, and it will be the same as the standard deviation of any other set of 10 consecutive odd integers.
