let makeGrayscalePixel(avgRGB:int) =
  [avgRGB; avgRGB; avgRGB]

let getAverageRGBValue(pixel:int list) =
  let sum = List.sum pixel
  let average = sum/3
  average // Return calculated average

let getPixel(pixRow:int list) =
  let r = pixRow.Head
  let g = pixRow.Tail.Head
  let b = pixRow.Tail.Tail.Head
  [r, g, b] // Return int list with RGB values in it

let TransformGrayscale(image:int list list) =
  let pixel = getPixel(image.Head)
  let avgRGB = getAverageRGBValue(pixel)
  let grayPixel = makeGrayscalePixel(avgRGB)
  //finish...