These two triangles are similar .find side lengths a and b .the two figures are not drawn to scale

Identify the type of observational study described. a statistical analyst obtains data about ankle injuries by examining a hospital's records from the past 3 years. cross-sectional retrospective prospective

Given the two similar triangles, how do i find the missing length? if a=4, b=5, and b'=7.5 find a'

Afrequency table of grades has five classes (a, b, c, d, f) with frequencies of 3, 13, 14, 5, and 3 respectively. using percentages, what are the relative frequencies of the five classes?