Part A is answer choice C, and Part B is answer choice A, because each square is one unit and 6 units are shaded out of 16 total shaded units, and 2/4 times 3/4 gives you 6/16, therefore 6 out of 16 is the correct answer.
i believe the answer is 13.85
Approximately 1718 have a score within that range.
We calculate the z-score for each end of this spectrum:
z = (X-μ)/σ = (2.5-3.1)/0.3 = -0.6/0.3 = -2
Using a z-table (http://www.z-table.com) we see that the area to the left of, less than, this z-score is 0.0228.
For the upper end:
z = (3.7-3.1)/0.3 = 0.6/0.3 = 2
Using a z-table, we see that the area to the left of, less than, this z-score is 0.9772.
The probability between these is given by subtracting these:
0.9772 - 0.0228 = 0.9544.
This means the proportion of people that should fall between these is 0.9544:
0.9544*1800 = 1717.92 ≈ 1718
