Angela scored in the 90th percentile of her class math test. If 27 students scored the same as or lower than she did, how many students are in the class?
90% of the class = 27
27/.90 = 30
check the 90th percentile means 90% scored at or below. So.. of 90% of 30 does = 27
27
To determine how many students are in Angela's class, we need to find the total number of students who took the math test.
The 90th percentile indicates that Angela scored better than or equal to 90% of the students in her class. In other words, only 10% of the students scored higher than Angela.
Since 27 students scored the same or lower than Angela, this means that 10% of the class is equal to 27 students.
To find the total number of students in the class, we can set up a proportion:
10% of the class = 27 students
100% of the class = ?
To find the missing percentage (100% of the class), we can use cross-multiplication.
(10% of the class) * (100% of the class) = (27 students) * (1)
Simplifying the equation:
10% * 100% = 27
1% = 27
Now, since we know that 1% represents 27 students, we can find the total number of students in the class by setting up another proportion:
1% of the class = 27 students
100% of the class = ?
(1% of the class) * (100% of the class) = (27 students) * (100)
Simplifying the equation:
1 * 100% = 27 * 100
100% = 2700
Therefore, there are 2700 students in Angela's class.