(Ch12-prob set-Q11) please answer all questions. Numerical values go up to the 3rd decimal place.

You are interested in testing the hypothesis that babies who travel in parent-facing strollers have different expressive vocabularies than babies who travel in away-facing strollers. You randomly assign 13 newborns to parent-facing strollers and 13 newborns to away-facing strollers. You then test the babies' expressive vocabularies at age 36 months using the Expressive Vocabulary Test (EVT), which is designed primarily to assess children's expressive vocabulary. The sample means and sums of squares of the scores for each of the groups are presented in the following table. Group Sample Mean Sum of Squares Away-facing 98.7 2,628.48 Parent-facing 102.4 2,122.68 You decide to use an ANOVA at a = 0.01 to test the null hypothesis that there is no difference between the groups. The ANOVA table follows. Calculate the F-ratio and enter it into the table. ANOVA Table Source of Variation Sum of Squares Degrees of Freedom Mean Square Between Treatments 86.99 88.99 Within Treatments 4,751.16 24 197.97 Total 4,840.15 25 Fcritical at o = 0.01 is Now evaluate the null hypothesis that the population means for all treatments are equal, At a significance level of a = 0.01, the null hypothesis is You find that you conclude that the direction that the stroller faces influences a child's expressive vocabulary at 36 months. Now you decide to use a t test to test the hypothesis that there is no difference between the groups. The estimated standard error (5MI -M2) is 5.52, so the t test statistic is Use the following tool to find the critical regions for a = 0.01. The critical t-scores (the values for t-scores that separate the tails from the mainibody of the distribution, forming the critical regions) are Now use the tool to evaluate the null hypothesis. At a significance level of o = 0.01, the null hypothesis is ily . You find that you conclude that the direction the stroller faces influences a child's expressive vocabulary at 36 months. When you evaluated the mean difference from the independent-measures study comparing only two samples, the ANOVA and the t test resulted in condusion