Answer:
0.0548
Step-by-step explanation:
The distribution of life span for a certain type of battery is approximately normal with mean 2.5 hours and standard deviation 0.25 hour.
To find the the probability that a selected battery will have a life span of at most 2.1 hours, we need to first determine the z-score for x=2.1 hours using
We substitute the values to get:
We read read -1.6 from the standard normal distribution table to get:
P(X≤2.1)=0.0548
pack of 30:
7.97/30=.27 per pencil
pack of 12:
4.77/12=
.40 per pencil
The best buy is pack of 30 because:
.27<.40
The question is incomplete, the complete question is;
If in 0.5 min the tank gets 0.8 gallons of the water then
how many gallons will be in 1 min ?
how many gallons will be in 3 min?
and how long it takes for 40 gallons?
Answer:
1.6 gallons
4.8 gallons
25 mins
Step-by-step explanation:
This question has to do with proportion.
If it takes 0.5 mins for the tank to get 0.8 gallons
in 1 minute the tank will get 0.8 * 1/0.5 = 1.6 gallons
In 3 minutes the tank will get 3 * 1.6 gallons = 4.8 gallons
if it takes 1 min to get 1.6 gallons
it will take x mins to get 40 gallons
x = 1 * 40/1.6 = 25 mins
Answer:
Its below!
Step-by-step explanation:
a=l*w
9=(3+x) (2+x)
9=6+3x+2x+x^2
9=6+5x+x^2
3=5x+x^2
Hope this helps!! :)
