Estimating Average Ocean Current Speed Using Trapezoidal Rule

[chukie]

Ocean currents (miles/hr) at a certain location are given below

Time of day: Speed mph:
8:00 am 17
8:10 am 20
8:20 am 22
8:30 am 21
8:40 am 17

How can I estimate the average river current speed from 8:00 am to 8:40 am using the trapezoidal rule? I tried but I got a huge number.

 

[Defennder]

What exactly did you do? Did you draw out the speed-time graph of these points and then attempt to find the area underneath after connecting all the dots?

 

[chukie]

What exactly did you do? Did you draw out the speed-time graph of these points and then attempt to find the area underneath after connecting all the dots?

I converted 8:40 into hours so 40/60=2/3
Then I supposed 0 to be 8:00, so the equation I had was integral sign 0 to 2/3 S(t) dt.
Then using the data in the chart: (17+2(20)+2(22)+2(21)+17)
Then I multiplied that sum by 1/(b-a) to get the average, and I got a number in the hundreds.

 

[chukie]

nvm i got it