Answer: answer is yes
Step-by-step explanation:
Answer:
the probability is 69.15%
Step-by-step explanation:
We have that the mean is 38 inches (m) and the standard deviation is 2 inches (sd), so we are asked:
P (x <39)
P ((x - m) / sd <(39 -38) /2)
P (z <0.5)
If we look in the normal distribution table we have to:
P (x <39) = 0.6915
That is, the probability is 69.15%
Answer:
16 3/5
Step-by-step explanation:
thank divinesworldtv they have the right answer
75 divided by 3 because for every 75 fish 3 are tagged 1,217 (rounded up from 1,216.6 repeating)
Answer:
30 mph
Step-by-step explanation:
Let d = distance (in miles)
Let t = time (in hours)
Let v = average speed driving <u>to</u> the airport (in mph)
⇒ v + 15 = average speed driving <u>from</u> the airport (in mph)
Using: distance = speed x time
![\implies t=\dfrac{d}{v}](https://tex.z-dn.net/?f=%5Cimplies%20t%3D%5Cdfrac%7Bd%7D%7Bv%7D)
Create two equations for the journey to and from the airport, given that the distance one way is 18 miles:
![\implies t=\dfrac{18}{v} \ \ \textsf{and} \ \ t=\dfrac{18}{v+15}](https://tex.z-dn.net/?f=%5Cimplies%20t%3D%5Cdfrac%7B18%7D%7Bv%7D%20%20%5C%20%5C%20%5Ctextsf%7Band%7D%20%5C%20%5C%20%20t%3D%5Cdfrac%7B18%7D%7Bv%2B15%7D)
We are told that the total driving time is 1 hour, so the sum of these expressions equals 1 hour:
![\implies \dfrac{18}{v} +\dfrac{18}{v+15}=1](https://tex.z-dn.net/?f=%5Cimplies%20%5Cdfrac%7B18%7D%7Bv%7D%20%2B%5Cdfrac%7B18%7D%7Bv%2B15%7D%3D1)
Now all we have to do is solve the equation for v:
![\implies \dfrac{18(v+15)}{v(v+15)} +\dfrac{18v}{v(v+15)}=1](https://tex.z-dn.net/?f=%5Cimplies%20%5Cdfrac%7B18%28v%2B15%29%7D%7Bv%28v%2B15%29%7D%20%2B%5Cdfrac%7B18v%7D%7Bv%28v%2B15%29%7D%3D1)
![\implies \dfrac{18(v+15)+18v}{v(v+15)}=1](https://tex.z-dn.net/?f=%5Cimplies%20%5Cdfrac%7B18%28v%2B15%29%2B18v%7D%7Bv%28v%2B15%29%7D%3D1)
![\implies 18(v+15)+18v=v(v+15)](https://tex.z-dn.net/?f=%5Cimplies%2018%28v%2B15%29%2B18v%3Dv%28v%2B15%29)
![\implies 18v+270+18v=v^2+15v](https://tex.z-dn.net/?f=%5Cimplies%2018v%2B270%2B18v%3Dv%5E2%2B15v)
![\implies v^2-21v-270=0](https://tex.z-dn.net/?f=%5Cimplies%20v%5E2-21v-270%3D0)
![\implies (v-30)(v+9)=0](https://tex.z-dn.net/?f=%5Cimplies%20%28v-30%29%28v%2B9%29%3D0)
![\implies v=30, v=-9](https://tex.z-dn.net/?f=%5Cimplies%20v%3D30%2C%20v%3D-9)
As v is positive, v = 30 only
So the average speed driving to the airport was 30 mph
(and the average speed driving from the airport was 45 mph)