Answer:
C≈27 feet
Step-by-step explanation:
A=πr²
A/π=r²
√A/π =r or –√A/π=r (refused)
then r =√(A/π) =√(58/π) =4.297829403 feet
C=2πr=2π(4.297829403)=27.00405856≈27 feet
Wilda can do the job in 4 hours ... she does 1/4 (or 0.25) of it each hour.
Karla can do it in 5 hours ... she does 1/5 (or 0.2) of it each hour.
Wilda worked alone for 1 hour ... 0.25 of the job was done before her helper
arrived. So only 0.75 of the job remained to be done together.
Working together, they accomplish (0.25 + 0.2) = 0.45 of the job in 1 hour.
How many times do they need to do 0.45 of the job in order to finish
the 0.75 of it that remains ? That's the number of hours it will take them,
working together.
0.75 / 0.45 = <em>1 and 2/3</em>
After Wilda worked alone for 1 hour and Karla came along to join her, it will
take them another <em>1 hour and 40 minutes</em> to finish the job and go for a swim.
Answer:
And if we use the values obtained we got:
For this case this value means that the expected score is about 7.48
Step-by-step explanation:
For this case we assume the following probability distribution:
X 5 6 7 8 9 10
P(X) 0.05 0.15 0.33 0.28 0.12 0.07
First we need to find the expected value (first moment) and the second moment in order to find the variance and then the standard deviation.
In order to calculate the expected value we can use the following formula:
And if we use the values obtained we got:
For this case this value means that the expected score is about 7.48
In order to find the standard deviation we need to find first the second moment, given by :
And using the formula we got:
Then we can find the variance with the following formula:
And then the standard deviation would be given by:
The answer to you question is B