Help on these problems please for my test

Shania's test scores in 8 subjects were 88, 91, 85, 74, 69, 72, 80, and 87. shania found the middle number of her scores. which type of measure did she find?

Item 1 solve for s. s+24=90 −114 −66 66 114

Find an bif a = {3, 6, 9, 12) and b = {2, 4, 6, 8, 10).