n alpha=0.05 alpha=0.01 4 0.950 0.990 5 0.878 0.959 6 0.811 0.917 7 0.754 0.875 8 0.707 0.834 9 0.666 0.798 10 0.632 0.765 11 0.602 0.735 12 0.576 0.708 13 0.553 0.684 14 0.532 0.661 15 0.514 0.641 16 0.497 0.623 17 0.482 0.606 18 0.468 0.590 19 0.456 0.575 20 0.444 0.561 21 0.433 0.549 22 0.423 0.537 23 0.413 0.526 24 0.404 0.515 25 0.396 0.505 26 0.388 0.496 27 0.381 0.487 28 0.374 0.479 29 0.367 0.471 30 0.361 0.463 35 0.334 0.430 40 0.312 0.403 45 0.294 0.380 50 0.279 0.361 55 0.266 0.345 60 0.254 0.330 65 0.244 0.317 70 0.235 0.306 75 0.227 0.296 80 0.220 0.286 85 0.213 0.278 90 0.207 0.270 95 0.202 0.263 100 0.197 0.256

(d) Use the table of critical values for the Pearson correlation coefficient to make a conclusion about the correlation coefficient. Let a = 0.01. The critical value is Therefore, there sufficient evidence at the 1% level of significance to conclude that between children's ages and the number of words in their vocabulary. (Round to three decimal places as needed.)