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
I got 18 I am not sure if it is right
Answer: 274/3 and 137 ft
Step-by-step explanation:
Total fence used: 548 ft
So, perimeter will be 548 ft, including the fence that divides the land.
Consider the playground the drawing below.
__________x________
| |
| | y
| |
|__________________|
Let's consider that the playground is going to be divided parallel to y (and there's no problem, because if you choose parallel to x, the area will be the same). So, the perimeter (the sum of all sides) will be:
2x + 3y = 548
And the area
A = x.y
Isolating x, we have:
x = (548 - 3y)/2
Substituting the x in the Area equation:
A = (548 - 3y)/2 . y = 548y - 3y²/2 = 274y - 3/2y²
A = 274y - 3/2y²
So, it's a quadratic function. And, to find out the maximum area that the playground can have, we need to find the y-vertex of the parabola: y-vertex = Δ/4a
a = -3/2 b = 274 c = 0
Δ = 274² - 4.(-3/2).0 = 274² = 75076
Amax = -Δ/4a = -75076/4.(-3/2) = 75076/6 = 12512.7 ft²
y = -b/2a = -274/2.(-3/2) = 274/3 ft
x = (548 - 3y)/2 = (548 - 3.274/3)/2 = 274/2 = 137 ft
Answer:
300 meters per minute
Step-by-step explanation:
Step 1
Determine the fraction of the total distance for each part of the race.
Given:
1st part of race = 4/9 of total distance
2nd part of race = 2/5 of remaining distance
Step 2
Determine the distance of the third part of the race.
Given:
time = 15 minutes
speed = 300 meters per minute
Step 3
If the third part of the race (which is 1/3 of the total distance) is 4500m, then the distance of the whole race is:
Step 4
Determine the distance of the 1st part of the race:
Step 5
Determine the speed of the 1st part of the race:
Given:
time = 20 minutes
distance = 6000 m
The capacity of the tank in gallons is 24 gallons.
<h3>What is an Equation ?</h3>
An equation is a mathematical statement formed when two algebraic expressions are equated by an equal sign.
It is given in the question that
When four gallons are added to a tank that is one-third full
the tank is then one-half full.
Let the capacity of the tank is x gallons
The equation can be formed for the capacity of the tank as
(1/3)x +4 = (1/2)x
(1/3)x -(1/2)x = -4
(1/6)x = 4
x = 24 gallons.
Therefore the capacity of the tank in gallons is 24 gallons.
To know more about Equation
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