Abby's average after taking 31 quizzes is 76. After her teacher drops Abby's 3 lowest test scores, her average increases to 81. What is the average of Abby's three lowest test scores?

29.3

Step-by-step explanation:

Abby's average after taking 31 quizzes is 76.

Total test scores= 31 × 76 = 2356

After Abby's teacher drops her 3 lowest test scores, her average increases to 81. This means that (31-3)= 28 test scores were used.

Total scores = 28 × 81 = 2268

Sum of Abby's three lowest score

= 2356 - 2268

= 88

Average of the three scores will now be 88 divided by 3

= 88/3

= 29.3

The average is 29.3

up

step-by-step explanation:

the orientation of the parabolas can easily be found by analysing the power of x and y and their signs. if x is squared , parabola opens up and also if its coefficient is negative it opens down. if y is squared , the parabola opens right and also if its coefficient is negative it opens left. however in order to do the above analysis our equation must be in standard form .

our parabola is

which is not standard form of any parabola . hence we square on both hand side and convert it into standard form.

hence we see that x is squared and its coefficient is non negative . there for it opens up.