Answer:
25th percentile = 202
80th percentile = 285
Step-by-step explanation:
Rearranging the values in increasing order
164
171
175
202
217
226
231
241
257
261
269
273
285
296
311
N = total number of variables = 15.
25th percentile = [(N + 1)/4]th variable = (15 + 1)/4 = 4th variable.
So, the 25th percentile = 4th variable = 202.
80th percentile = 0.8(N + 1) th variable = 0.8 × (15 + 1) = 12.8th variable = 13th variable = 285
Answer:
B. (x+4)(x+i)(x-i)
Step-by-step explanation:
Let 
We can factor this polynomial by grouping:
We factor further to obtain:
We apply difference of two squares to get:
Answer:
90,000
Step-by-step explanation:
this is wrong
To find the perimeter of a rectangle, add the lengths of the rectangle's four sides. If you have only the width and the height, then you can easily find all four sides (two sides are each equal to the height and the other two sides are equal to the width). Multiply both the height and width by two and add the results.
When ever you have percentages, it should be helpful to bear in mind you can express them as multipliers. In this case, it will be helpful.
So, if we let:
a = test score
b = target score
then, using the information given:
a = 1.1b + 1
a = 1.15b - 3
and we get simultaneous equations.
'1.1' and '1.15' are the multipliers that I got using the percentages. Multiplying a value by 1.1 is the equivalent of increasing the value by 10%. If you multiplied it by 0.1 (which is the same as dividing by 10), you would get just 10% of the value.
Back to the simultaneous equations, we can just solve them now:
There are a number of ways to do this but I will use my preferred method:
Rearrange to express in terms of b:
a = 1.1b + 1
then b = (a - 1)/1.1
a = 1.15b - 3
then b = (a + 3)/1.15
Since they are both equal to b, they are of the same value so we can set them equal to each other and solve for a:
(a - 1)/1.1 = (a + 3)/1.15
1.15 * (a - 1) = 1.1 * (a + 3)
1.15a - 1.15 = 1.1a + 3.3
0.05a = 4.45
a = 89
