10 students averaged 80, so the sum of their scores was (10 x 80) = 800
20 students averaged 89, so the sum of their scores was (20 x 89) = 1,780
All together, the sum of all 30 scores was (800 + 1,780) = 2,580
30 students totaled 2,580, so their average was (2,580 / 30) = <em> 86</em> .
Answer:
all
Step-by-step explanation:
all of them has the probability
<span>Half-span is half of span. Pitch of the roof is calculated as rise/(span/2). In this case, rise is 8 feet and span is 30 feet. So, the pitch can be calculated as 8/(30/2) or 8/15. Pitch is normally represented as the number of inches of rise per foot. So, to reduce 8/15 to match a foot, we multiply it by 12. So, (8/15) * 12 gives us 6.4 inches of rise per foot.</span>
Where is the table. We need a table. We also need to type 20 words to ask...
