Its C. 15 x ? = 405 The question is kind of like writing a fact family. You need to find the same unknown number that belongs in the question mark in the rest of them. So since 405 ÷ 15 = 27, C. 15 x 27 = 405 ? = 27 (It also needs to make sense :P)
to find the mean, we must add al the numbers and divide it by n
that is,
164,175,178,166,167,145,176,150,174,162,180,156,173,158,182,184,160,172,186,168,195,169,171,187,170 we have to add al these numbers and divide it by 25
