Find the critical value :0\Don't construct a confidence interval: A psychology professor at a certain college gave a test to the students in her class. The test was designed to measure students' attitudes toward school, with higher scores indicating a more positive attitude. There were 30 students in the class, and their mean score was 78. Scores on this test are known to be normally distributed with a standard deviation of 10. Explain why these data should not be used to construct a confidence interval for the mean score for all the students in the college. .The sample size is too small, and we do not know the population is approximately normal. 0 The sample is not randomly selected to represent the students in the college. 0 This is proportion data, not mean data. 0 The standard deviation is too small relative to the mean. Interpret a confidence interval: A survey organization drew a simple random sample of 625 households from a city of 100,000 households. The sample mean number of people in the 625 households was 2.30, and a 95% confidence interval for the mean number of people in the 100.000 households was 2.16