Answer:
The top 20% of the students will score at least 2.1 points above the mean.
Step-by-step explanation:
When the distribution is normal, we use 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.
The mean of a certain test is 14 and the standard deviation is 2.5.
This means that 
The top 20% of the students will score how many points above the mean
Their score is the 100 - 20 = 80th percentile, which is X when Z has a pvalue of 0.8. So X when Z = 0.84.
Their score is:




16.1 - 14 = 2.1
The top 20% of the students will score at least 2.1 points above the mean.
"Nina and Ryan each ran at a constant speed for a 100-meter race. Each runner’s distance for the same section of the race is displayed..." Ryan had a head start of 10 meters.
This is further explained below.
<h3>Who had a head start, and how big was the head start?</h3>
Generally, To help low-income children and their families, the United States government funds a program called Head Start, which offers a variety of services including early childhood education, health care, nutrition education, and parent engagement.
In conclusion, who had a head start, and how big the head start was is; Ryan had a head start of 10 meters.
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There is a designated formula for this circle drawing. This is a secant-secant scenario, and in this case, the formula is:
CD(CD+X)=CB(CB+AB)
Plug the values in.
AB=42
BC=18
CD=4
4(4+x)=18(18+42)
Solve for x.
16+4x=1080
4x=1064
x=266
Your answer is C
Answer:
B. -1
Step-by-step explanation:
x^3-4x^2+2x+10=x^2-5x-3
We know it has 3 roots since it is a 3rd degree polynomial.
Two of the roots are (3+2i) and (3-2i)
Subtract x^2-5x-3 from both sides
x^3-4x^2+2x+10-(x^2-5x-3)=x^2-5x-3 -(x^2-5x-3)
Distribute the minus sign
x^3-4x^2+2x+10-x^2+5x+3=x^2-5x-3 -x^2+5x+3
x^3 -5x^2+7x +13 =0
Graphing this equation , we see that it crosses the x axis at x=-1
That covers the three roots, 1 real and two complex