A study was done to determine the mean number of pets per household in a certain city. For the 60 households surveyed, the sample  was mean 2.1 pets and the sample standard deviation was 0.7 pets.  The distribution to use to calculate the 95% confidence interval is ________________.  

A study is done to determine the mean time that it takes an order to be filled at a drive-thru window.  The fulfilment times for 500 customers at a drive-thru window are recorded and this results in a 90% confidence interval of 92.4 seconds to 96.3 seconds. Which of the following best expresses the meaning of this confidence interval?  

Determine whether the underlined value represents a parameter or a statistic and why.  86% of all SMC students are from California. 

Suppose you want to test the claim that μ > 25.6. Given a sample size of n = 43 and a level of significance ofα = 0.10, when should you reject the null hypothesis?

A random sample of SMC math students are asked how much time (in minutes) they spend on math homework per day.  The responses are listed below.  Calculate the 95% confidence interval for the mean time an SMC math students spend on homework per day.  Assume that the conditions are met to calculate the interval.  Round the end points of the interval to one decimal place.  The units of the interval are minutes.  41     61     65     71     72     77     56     52     58     52

A study is to be done to determine the proportion of colleges graduates that would choose a different major if they could go back and redo college.  What minimum  sample size should be used if the study will have a 4.4% margin of error and a 90% confidence level?  

A city wants to determine the mean amount that residents pay in property taxes each year. At least how many residents should be polled to determine the mean property tax to within $2000 at 95% confidence? Assume that the city has estimated the standard deviation in property tax paid to be $35000.  

Suppose you want to test the claim that μ < 35.7. Given a sample size of n = 31 and a level of significance ofα = 0.01, when should you reject the null hypothesis ?

Determine whether the sampling method is independent or dependent.  Indicate whether the response variable is qualitative or quantitative.  A study on housing polled 100 random people aged 20 – 29 who live in Los Angeles and 100 random people aged 20 – 29 who live in New York to see if they planned to purchase a home (Yes or No) in the next 5 years.  The two proportions will be compared. 

When computing the confidence interval for the population mean, how does decreasing the sample size affect the margin of error in the confidence interval?