所有的GRE考试Subject Test: Math Resources
Example Questions
Example Question #601 :Gre Subject Test: Math
people are at a farewell party. At the end of the night, each person shakes hands. How many handshakes are made?
NOTE: No two people can shake hands more than once.
Step 1: Determine how many people are there..
There arepeople.
Step 2: Determine how many people shake hands in a handshake...
people make one handshake.
Step 3: Determine how many handshakes can be made...
We have a restriction here, so we need to use permutation..
So, there will behandshakes.
handshakes
Example Question #602 :Gre Subject Test: Math
In how many ways can I rearrange the letters in the word "ANACONDA"?
Step 1: Count how many letters are in the word ANACONDA...
There are 8 letters.
Step 2: Count how many repeats of any letters (if any)..
There areA's andN's.
Step 3: Find how many ways I can rearrange...
Example Question #603 :Gre Subject Test: Math
How many ways can I arrange the letters in the word?
Step 1: Count how many numbers are in the word...
There areletters.
Step 2: Count the number of repeated letters...
There areT's
There areO's
There areR's
Step 3: To find how many ways I can arrange the letters, take the factorial of the total number of letters and divide it by the factorial of how many times a certain letter repeats...
So,
Example Question #1 :Uniform Distribution
X is a continuously and uniformly distributed on the interval (0,50). Find the Expected Value (E[x]) and Variance (Var(x)) of X.
Because x is a continuous uniform random variable the expected value and variance can be found with the following formulas:
X is uniform on (a,b). In this case a is 0 and b is 50. Plugging the values of a and b into the given formulas will give the answers:
Example Question #1 :Binomial Distribution
A fair coin is tossed 15 times. What is the probability of observing less than 3 heads?
This problem uses the Binomial Distribution:
For this problem n is the number of trials, or 15. Because the problem stated that the coin was a fair coin the probability of heads is one half, or .5.
The binomial distribution is a discrete distribution so the expression x<3 has to be broken down.
Adding the probabilities will give the final answer.
Example Question #2 :How To Find Z Scores For A Data Set
The average score on the statistics final exam was 85 and the standard deviation was. Chris scored a. Chris scored higher than what percent of his class?
The first step in this problem is calculating the z-score.
The next step is to look up 4 in the z-table. The value from the table is.
Example Question #3 :How To Find Z Scores For A Data Set
What is the-score for a value of 115 when the mean of the population is 103 and the standard deviation is 8?
A-score indicates whether a particular value is typical for a population or data set. The closer the-score is to 0, the closer the value is to the mean of the population and the more typical it is. The-score is calculated by subtracting the mean of a population from the particular value in question, then dividing the result by the population's standard deviation.
Example Question #4 :How To Find Z Scores For A Data Set
A population of values has a mean of 43 and a standard deviation of 12. One of the values in the population is 49. What is the Z-score for that value?
A Z-score indicates whether a particular value is typical for a population or data set. The closer the Z-score is to 0, the closer the value is to the mean of the population and the more typical it is. The Z-score is calculated by subtracting the mean of a population from the particular value in question, then dividing the result by the population's standard deviation.
Example Question #5 :How To Find Z Scores For A Data Set
The z-score is also known as the standard score.
The average temperature for all the days preceding the last for the month of February was 55 degrees Farhenheit, with a standard deviation of 5 degrees.
On the last day, the temperature was 73 degrees F. What is the z-score for the temperature on the last day?
To find the z-score, follow the formula
or
Example Question #6 :How To Find Z Scores For A Data Set
A population has a standard deviation ofand a mean of. One of the values in the population is. What is the z score for that value?
A z score is unique to each value within a population.
To find a z score, subtract the mean of a population from the particular value in question, then divide the result by the population's standard deviation.
Certified Tutor