In the general population, the mean IQ score is 100, with standard deviation σ = 15. A random sample of 36 newly tested incoming students at Community College revealed a sample mean IQ of 104.5. Does this sample give good evidence (at a 5% level of significance) that the mean IQ of all incoming students is different from 100?

An investigator is using a chi-square test to compare the proportion of patients with a successful recovery after receiving one of 4 treatments.  There were 25 subjects in each group. What is the critical value for testing no association or treatment and response?

According to a recent article about individuals who have credit cards, the mean number of cards per person with credit cards is 4.5. To test this result a random survey of 60 individuals who have credit cards was conducted. The survey only includes the number of credit cards per participant. The results of the survey are attached below. (a) What is the variable of interest in this study? Is it qualitative or quantitative? (b) Do the results of the survey imply that the mean number of cards per individual is less than 4.5? Use the a = 0.05 level of significance. E Click the icon to view the data from the survey. (a) What is the variable of interest in this study? Is it qualitative or quantitative? The variable of interest is number of credit cards.It is a quantitative variable. (b) Do the results of the survey imply that the mean number of cards per individual is less than 4.5? Use the a = 0.05 level of significance. State the null and alternative hypotheses. Họ: H = 4.5 < 4.5 H1: H…

A survey among freshmen at a certain university revealed that the number of hours spent studying the week before final exams was normally distributed with mean 25 and standard deviation 9.  Between what two values are the middle 80% of the hours spent studying?