Answer:
x = 12
Step-by-step explanation:
Given a tangent and a secant from an external point to the circle, then
The square of the tangent is equal to the product of the external part of the secant and the entire secant, that is
x² = 8(8 + 10) = 8 × 18 = 144 ( take the square root of both sides )
x = = 12
Answer:
Grades between 62 and 64 result in a D grade.
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:
Find the numerical limits for a D grade.
D: Scores below the top 84% and above the bottom 10%
So below the 100-84 = 16th percentile and above the 10th percentile.
16th percentile:
This is the value of X when Z has a pvalue of 0.16. So X when Z = -0.995.
10th percentile:
This is the value of X when Z has a pvalue of 0.1. So X when Z = -1.28.
Grades between 62 and 64 result in a D grade.