A+ Answers

1)         Northeastern University (NU) wants to analyze the summer break party habits of its students during college relative to during high school (HS). A random sample of 9 NU students was taken.  The sample reveals the following number of parties attended during summer break:

            During HS       1          3          5          3          1          1          3          3          2

            During NU      0          8          3          2          7          4          7          3          6

            D = NU - HS   -1         5          -2         -1         6          3          4          0          4

            D2       1          25        4          1          36        9          16        0          16

At the .05 level of significance, is there evidence a NU student parties more, on average, during college than during HS summer break?  (Assume the population of differences follows a normal distribution.)

2)         NU wants to estimate the proportion of its 1,000 student athletes that play sports during the summer break.  If a random sample of 100 student athletes reveals 70 play sports during the summer break, construct a 95 percent confidence interval estimate for the population proportion of NU student athletes that play sports during the summer break.

3)         NU wants to estimate the mean time spent by its students commuting daily to campus.  The population standard deviation time spent commuting is 8 minutes.  A random sample of 49 students reveals a mean of 20.5 minutes. 

Construct a 99 percent confidence interval estimate for the population mean time spent by NU students commuting daily to campus. 

4)         NU wants to analyze the study habits of its students attending CPS relative to its students attending the Day School (DS).  Random samples of 9 students are taken from CPS and DS.  The two samples reveal the following data:

Daily hours studying attending CPS  2  2  3  2  3  2  1  1  2 

Daily hours studying attending DS                6  3  0  3  6  0  2  3  4 

At the .05 level of significance, is there evidence a student attending CPS spends less time studying, on average, than a student attending DS?  (Assume both populations of student time spent studying follow a normal distribution and have equal variances.)