Laura is enrolled in a one semester computer applications class. She achieves grades of 70, 86, 81, and 83 on the first four exams. The final exam counts the same as the four exams already given.
If x represents the grade on the final exam, write an expression that represents her course average.
If Laura's average is greater than or equal to 80 and less than 90, she will earn a B in the course. Write a compound
inequality that must be satisfied to earn a B and solve the inequality.

Laura will need to grade more than 80 in the final exam to earn a B

Step-by-step explanation:

Average Value

The mean or average of a data set is found by adding all numbers and then dividing by the number of values in the set. Written as a formula:

Where xi is the value of each data and n is the total number of values.

Laura has the grades of 70, 86, 81, and 83 in computer applications class. If we call x to the grade on the final exam, then the sum of her grades is:

The average of her grades is:

For Laura to earn a B the average must be greater than or equal to 80 and less than 90. Thus:

This is the inequality that must be satisfied. Now we solve it.

Multiply by 5:

Operating:

Subtracting 320:

Laura will need to grade more than 80 in the final exam to earn a B

answer: 457.14

step-by-step explanation:

205 - 45 = 160

160 / .35 = 457.142857

step-by-step explanation:

circumference divided by 3.141592654 then timesthe radius twice