8.49 x 10⁻⁷ = 0.000000849
If a number is positive, Leila's theory that 75% of a number will always be greater than 50% of another number is <em>true</em>;<em> </em>however, if both numbers are negative, or if the number of which she finds 50% is much greater than the number of which she finds 75%, Leila's theory could be incorrect.
This inequality shows that Leila is correct:

(which simplifies to

)
This inequality shows that Leila is incorrect:

(which simplifies to

)
Hope this helps!
Total students 5+16+42+22+5 = 90
0-1's probability is 5 / 90 = 5.5% about
2-3's probability is 16 / 90 = 17.7% about
4-5's probability is 42 / 60 = 46.6% about
6-7's probability is 22 / 90 = 24.4% about
8+'s probability is 5 / 90 = 5.5% about
(percentages not rounded, just cut off at the first decimal)
Answer:
Less than 8 hours
Step-by-step explanation:
Kahn