Open this web, the web is really - really helps....................................
http://www.coolmath.com/algebra/08-lines/11-finding-equation-line-point-slope-01
So we are given that the mean is 42% and the sd (standard deviation) is 8%
Assuming our data is normal we can use the 68-95-99 rule
So one thing you should realize is that 42% + 8% is 50% which is passing. That is one standard deviation higher. So we use:
100 - 68 - 13.5 - 2.35 - 0.15 = 16. That means 16% of students passed the test. Which is terrible. They probably need to hit the books more.
Anyways if you have any question feel free to message me!
Hopes this helps!
Answer:
60 minutes for the larger hose to fill the swimming pool by itself
Step-by-step explanation:
It is given that,
Working together, it takes two different sized hoses 20 minutes to fill a small swimming pool.
takes 30 minutes for the larger hose to fill the swimming pool by itself
Let x be the efficiency to fill the swimming pool by larger hose
and y be the efficiency to fill the swimming pool by larger hose
<u>To find LCM of 20 and 30</u>
LCM (20, 30) = 60
<u>To find the efficiency </u>
Let x be the efficiency to fill the swimming pool by larger hose
and y be the efficiency to fill the swimming pool by larger hose
x = 60/30 =2
x + y = 60 /20 = 3
Therefore efficiency of y = (x + y) - x =3 - 2 = 1
so, time taken to fill the swimming pool by small hose = 60/1 = 60 minutes
Bobby needs to grow at least 1 in to be more than 70 inches tall