4. You suspect that children are better than adults at short-term memory tasks. You place 12 different items on a tray. Ten randomly selected children and 10 randomly selected adults look at the tray for a minute and, five minutes later, you count the number of items that each was able to recall. For the 10 children, the mean number remembered was 8.1 objects, with standard deviation 3.6. For the 10 adults, the mean was 6.8, with standard deviation 2.1. a. Write the hypotheses for the appropriate test. Circle the best definition of the symbols you used. A. The number remembered by the adults and the number remembered by the children. B. The mean number of items remembered by these 10 adults and these 10 children if you could test them over and over. C. The mean number remembered by the randomly-selected adults and the mean number remembered by the randomly-selected children. D. The number of items that all children would remember and the number of items that all adults would remember, if you could test all children and all adults. E. The mean number of items that all children would remember and the mean number of items that all adults would remember, if you could test all children and all adults. b. Assume that Ho is true. Compute x₁ - *₂, from the samples. Then, using the SEEST of 1.32, put a scale on this sketch of the sampling distribution of 1-2. Finally, locate - from the samples with an arrow. c. Use StatCrunch to find the p-value for the test. Shade the area on the sampling distribution that represents the p-value. d. Using a = 5%, circle the capitalized word(s) in each pair to make an appropriate conclusion. REJECT / DO NOT REJECT Ho. It IS/IS NOT plausible that the mean number remembered is equal for adults and children. There IS / IS NOT statistically significant evidence that children, on average, remember more items than adults. If the null hypothesis is true, it's UNUSUAL / FAIRLY LIKELY to get a difference in means, children-adu, as larger or larger than you got from your samples.