A health educator wants to evaluate the effect of a dental film on the frequency with which children brush their teeth. A random selection of 8 children are used for the experiment. First, a baseline of the number of times the children brush their teeth over a month's period is established. Next, the children are shown the dental film and again the number of teeth brushings are recorded for a month. The following data are recorded. Assume you are evaluating H 0 with the t test.Using a = .05 2 tail , t crit = _________.
A) +2.365
B) ±2.365
C) ±2.145
D) +2.365.

Question

A health educator wants to evaluate the effect of a dental film on the frequency with which children brush their teeth. A random selection of 8 children are used for the experiment. First, a baseline of the number of times the children brush their teeth over a month's period is established. Next, the children are shown the dental film and again the number of teeth brushings are recorded for a month. The following data are recorded.  Assume you are evaluating H 0 with the t test.Using a = .05 2 tail , t crit = _________.
A) +2.365 
B) ±2.365 
C) ±2.145 
D) +2.365.

Quizplus · Accepted Answer

Since we are using a two-tailed t-test with a significance level of .05, we need to use the t-distribution table to find the critical value. With 8 degrees of freedom (n-1), we find that the critical value is ±2.306. However, this answer is not one of the choices provided. The closest option is B, ±2.365, which corresponds to 2.306 rounded to three decimal places. Therefore, we choose B as our answer.

A Health Educator Wants to Evaluate the Effect of a Dental