55% of the 300 students in 6th grade have a younger brother or sister. How many 6th graders have a younger sibling? A tape diagram. There are 55 6th graders with a younger sibling out of all 6th graders. There are question mark 6th graders with a younger sibling out of 300 all 6th graders. What steps should be used to find 55% of 300? Check all that apply. 100 x 3 = 300 55 x 3 = the answer 55 x 300 = the answer 55 x 300 = 18,000 students 55 x 3 = 165 students 165 6th graders have a younger sibling.