In a set of normally distributed test scores that have a mean of 100 and standard deviation of 15, it would be correct to conclude that approximately 68 percent of the scores would fall between and

It would be correct to conclude that approximately 68 percent of the scores would fall between 85 and 115.          

Step-by-step explanation:

We are given the following in the question:

Mean, μ = 100

Standard Deviation, σ = 15

We are given that the distribution is a bell shaped distribution that is a normal distribution.

Empirical rule

Also known as 68-95-99.7 rule.It states that almost all data lies within three standard deviation of mean for a normal distribution.About 68% of data lies within one standard deviation of mean.About 95% of data lies within two standard deviation of mean.About 99.7% of data lies within three standard deviation of mean.

Thus, approximately 68% of data will lie within one standard deviation of mean.

Thus, it would be correct to conclude that approximately 68 percent of the scores would fall between 85 and 115.

answer:

1/9

step-by-step explanation:

to answer this, we "complete the square."

start with x^2+x.

1. identify the coefficient of the x term; it is 1.

2. halve this result, obtaining 1/2, and then square the latter:   (1/2)² = 1/4

3.   add 1/4 to, and then subtract 1/4 from, the original x^2+x:

      x^2+x + 1/4 - 1/4 this is exactly equivalent to   x^2+x.

4.   strictly speaking, the answer to this problem is 1/4, since adding 1/4 to  

x^2+x makes x^2+x into a perfect square.