Respuesta :

94

(85+89+92+x)/4 = 90

(266+x)/4 = 90
(Multiply by 4 on each side to get rid of it)

266+x=360
(subtract 266 from each side)

x = 94


aachen

Answer:

94

Step-by-step explanation:

Given: Alexis recieved an 85,89,92on three tests

To Find: Number of points she needs to score in order to have an average of atleast 90.

Solution:

Let the marks scored by Alexis in next test = [tex]\text{x}[/tex]

Marks scored by Alexis in three test = [tex]85[/tex]

                                                               [tex]89[/tex]

                                                               [tex]92[/tex]

Sum of marks scored by Alexis = [tex]85+89+92[/tex]

                                                    =[tex]266[/tex]        

Average of Alexis's marks after next test = [tex]\frac{\text{Sum of marks of all tests}}{4}[/tex]

                                                                  =[tex]\frac{266+\text{x}}{4}[/tex]

To have average of at least 90

                                               [tex]\frac{266+\text{x}}{4}[/tex]≥90

                                               [tex]266+\text{x}\geq 360[/tex]

                                               [tex]\text{x}\geq 94[/tex]

Alexis needs to score atleast 94 to have an average of at least 90