Riley took 5 tests in science. Each test had a different score. The mean score of the tests was 90%. The median score of the tests was 85%. Based on this information, select the two statements that must be true. A: More than half of the scores were 85% or greater.
B: More than half of the scores were 90% or greater.
C: There were no scores less than 85%
D: There were no scores less than 90%
E: At least one score was exactly 85%
F: At least one score was exactly 90%

there are no answer choices

step-by-step explanation:

part a: 1.08

part b: 27.59

< xcy ≅ < xby

step-by-step explanation:

in δcax and δbax,

so, δcax ≅ δbax (side-angle-side or sas)

since δcax ≅ δbax, we can conclude < acx ≅ < abx

in δacy and δaby,

so, δacy ≅ δaby (side-angle-side or sas)

since δacy ≅ δaby, we can conclude < acy ≅ < aby

now,

< acy ≅ < aby

=> < acx + < xcy ≅ < abx + < xby

=> < acx + < xcy ≅ < acx + < xby   (since < acx ≅ < abx already proved above)

subtracting < acx from both sides, we get

< acx + < xcy -< acx ≅ < acx + < xby -< acx

cancelling out < acx and -< acx from both sides, we get

< xcy ≅ < xby (proved)