Answer:
The reading speed of a sixth-grader whose reading speed is at the 90th percentile is 155.72 words per minute.
Step-by-step explanation:
Problems of normally distributed samples are solved using the z-score formula.
In a set with mean
and standard deviation
, the zscore of a measure X is given by:

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.
In this problem, we have that:

What is the reading speed of a sixth-grader whose reading speed is at the 90th percentile
This is the value of X when Z has a pvalue of 0.9. So it is X when Z = 1.28.




The reading speed of a sixth-grader whose reading speed is at the 90th percentile is 155.72 words per minute.
Answer:
<em><u>Lines are perpendicular to each other .</u></em>
Step-by-step explanation:
Standard equation of line is : y = mx + c, Where m represents the slope
Given Equations :


Two lines are parallel if the slope of the lines are same.
Two line are perpendicular if the product of the slope = - 1
Clearly slopes are not equal , therefore the lines are not parallel.
product of the slope is - 1, therefore the lines are perpendicular.

Answer: 23x
Step-by-step explanation:
Answer:
or
.
Step-by-step explanation:
How are tangents and secants related to sines and cosines?
.
.
Sticking to either cosine or sine might help simplify the calculation. By the Pythagorean Theorem,
. Therefore, for the square of tangents,
.
This equation will thus become:
.
To simplify the calculations, replace all
with another variable. For example, let
. Keep in mind that
.
.
.
Solve this equation for
:
.
.
.
Given that
,
is the only possible solution.
,
, where
(i.e.,
is an integer.)
Given that
,
.
or
. Accordingly,
or
.