Answer:
23.1 hours
Step-by-step explanation:
the mean is calculated as
mean = ∑ fx ÷ ∑ f
where x is the midpoint of the time intervals
0 < h ≤ 10 ⇒ x = 5
10 < h ≤ 20 ⇒ x = 15
20 < h ≤ 30 ⇒ x = 25
30 < h ≤ 40 ⇒ x = 35
then
∑ fx = (5 × 5) + (15 × 15) + (50 × 25) + (10 × 35)
= 25 + 225 + 1250 + 350
= 1850
∑ f = 5 + 15 + 50 + 10 = 80
then
mean = 1850 ÷ 80 ≈ 23.1 hours (to 1 dp )
Answer:
Step-by-step explanation:
For example, the atmosphere mixes down into the other spheres and releases precipitates; the hydrosphere overlaps onto land surfaces and water vapor rises up into the atmosphere; the biosphere reaches up into the atmosphere, down into soils and rock, and throughout the oceans, exchanging gases, water and nutrients
Answer:
i believe its 1/6
Step-by-step explanation:
The difference of a number and 5 = n - 5
Twice that = 2(n - 5)
‘is’ is the equal sign, so the expression before is equal to 7.
Equation: 2(n - 5) = 7
Answer:
x = 5 and y = -5
Step-by-step explanation:
You can use algebra or graphing to solve this. I will be using algebra, with substitution.
Step 1: Move the 5 over in the 1st equation
3x + 2y = 5
x = y + 10
Step 2: Substitute in x
3(y + 10) + 2y = 5
Step 3: Distribute
3y + 30 + 2y = 5
Step 4: Combine like terms
5y + 30 = 5
Step 5: Move the 30 over
5y = -25
Step 6: Divide both sides by 5
y = -5
Step 7: Plug it back in into an original equation to find x
x = -5 + 10
x = 5
