A professor has recorded exam grades for 10 students in his class, but one of the grades is no longer readable. If the mean score on the exam was 80 and the mean of the 9 readable scores is 84, what is the value of the unreadable score?

The value of the unreadable score is 44.

Step-by-step explanation:

The mean is the sum of all the exams' scores divided by the number of exams. So

In which S is the sum of all the exams's scores and N is the number of exams.

In this problem, we have that:

10 students, so N = 10.

9 readable scores have a mean 84, there is also one unreadable score, so

Mean of 80, so M = 80.

We want to find x

The value of the unreadable score is 44.

the answer is: d) o, f, and kr.

atomic radius of bromine (br) is 114 pm.

atomic radius of oxygen (o) is 73 pm.

atomic radius of fluorine (f) is 72 pm.

atomic radius of krypron (kr) is 112 pm.

the atomic radius of a chemical element is a measure of the size of its atom.

the atomic radius varies with increasing atomic number, but usually increases because of increasing of number of electrons.

the atomic radius decreases across the periods because an increasing number of protons, because greater attraction between the protons and electrons.