9514 1404 393
Answer:
27 cm³
Step-by-step explanation:
The surface area of a cube is ...
SA = 6s²
Then the edge length is ...
54 cm² = 6s² . . . . . please note that cm³ is not the appropriate unit for area
9 cm² = s² . . . . . .divide by 6
3 cm = s . . . . . . . take the square root
The volume of a cube is ...
V = s³
V = (3 cm)³ = 27 cm³
The volume of the cube is 27 cm³.
Answer:
6.7% of children who finished the race in under 45 seconds.
Step-by-step explanation:
We are given the following information in the question:
Mean, μ = 75 seconds
Standard Deviation, σ = 20 seconds
We are given that the distribution of time of completion is a bell shaped distribution that is a normal distribution.
Formula:
P(finished the race in under 45 seconds.)
P(x < 45)
Calculation the value from standard normal z table, we have,

6.7% of children who finished the race in under 45 seconds.
Answer:

And we can use the cumulative distribution function given by:

And for this case we can write the probability like this:

And then the final answer for this case would be 
Step-by-step explanation:
For this case we define our random variable X "price of gasoline for a city in the USA" and we know the distribution is given by:

And for this case the density function is given by:

And we want to calculate the following probability:

And we can use the cumulative distribution function given by:

And for this case we can write the probability like this:

And then the final answer for this case would be 