Dr. Liu wants to learn how well the students in his research methods class performed on their final exam. He added together all 25 exam scores and then divided by 25. What measure of central tendency did Dr. Liu calculate?
A) modeB) medianC) meanD) standard deviation

What the teacher is calculating is called the mean. It's given by the sum of all the individual values divided by the number of instances.

Step-by-step explanation:

What the teacher is calculating is called the mean. It's given by the sum of all the individual values divided by the number of instances.

It can't be the mode, since that would be the value that most apear in the population. It also can't be the median, since that is the value that is exactly in the half of the population and it can't the standard deviation since that is how the values are dispersed from the mean.

∠1≅∠2 by the alternate exterior angles theorem.

step-by-step explanation:

given, a ∥ b and ∠1 ≅ ∠3 .we have to prove that e ∥ f

we know that ∠1≅∠3 and that a || b because they are given. we see that by the alternate exterior angles theorem. therefore, ∠2≅∠3 by the transitive property. so, we can conclude that e || f by the converse alternate exterior angles theorem.

we have to fill the missing statement.

transitivity property states that if a = b and b = c, then a = c.

now, given ∠1≅∠3 and by transitivity property ∠2≅∠3 .

hence, to apply transitivity property one angle must be common which is not in result after applying this property which is ∠1.

the only options in which ∠1 is present are ∠1 and ∠2, ∠1 and ∠4

∠1 and ∠4 is not possible ∵ after applying transitivity we didn't get ∠4.

hence, the missing statement is ∠1≅∠2.

so, ∠1≅∠2 by the alternate exterior angles theorem.

linear pair postulates