20. Confidence Interval for Comparing Keyboards The traditional keyboard configuration is referred to as a QWERTY configuration because of the positions of the letters QWERTY on the top row of keys. Developed in 1936, the Dvorak keyboard supposedly provides a more efficient arrangement by positioning the most used keys on the middle row where they are more accessible. A Discover magazine article suggested that you can measure the ease of typing by using this point-rating system: Count each letter on the home row as 0, count each letter on the top row as 1, and count each letter on the bottom row as 2. Using this rating system with each of the 52 words of the Preamble to the Constitution, we get the values listed in order below. Construct a 95%

confidence interval estimate of the difference between the means of the ratings for words using both systems. Does the result appear to support the claim that the Dvorak keyboard configuration is easier?

QWERTY Keyboard Dvorak Keyboard 2 2 5 1 2 6 3 3 4 2 4 0 5 7 7 5 6 6 8 10 2 0 3 1 0 0 0 0 2 0 4 0 3 4 0 3 3 1 3 5 7 2 2 10 5 8 2 4 4 2 6 2 6 1 7 2 7 2 3 8 2 0 4 1 5 0 4 0 1 3 0 1 0 3 0 1 2 0 0 0 1 5 2 5 2 14 2 2 6 3 1 7 0 1 0 3 0 1 2 0 0 0 1 4