1.a. mu=350; sigma=100
1.b. z=(365-350/100=0.15. Required area is (100-11.92/2=44.04%.
1.c. z=(250-350)/100=-1. Percentile rank is (100-68.27)/2=15.87 percentile.
1.d. n=26; SD(ybar)=100/sqrt(25)=20. 95% CI is:
		ybar plus/minus t(25,2.5)*SD(ybar)
		350 plus/minus 2.06*20
		[308.8, 391.2]

2.a. H0: mu=$62,500; Ha: mu<$62,500 
2.b. First, ybar=$60,000 is consistent. Assume H0 true and since n is
     large determine the z value. SD(ybar)=10000/sqrt(100)=1000 hence
     z=(60000-62500)/1000=-2.5. The p-value is 0.62% (or 0.0062 
     expressed as a probability) which is highly significant and so we
     reject the null hypothesis.
2.c. b=0.8(10000/5)=1600; a=60000-1600*20=28000. Hence the regression line
     equation is:
		income=28000 + 1600(yrs_of_tenure)
2.d. For unit increase in yrs_of_tenure we can expect income to 
     increase by $1600. The intercept indicates that a tenured faculty
     member with zero yrs_of_tenure can expect, on average, to earn
     $28,000 which may be reasonable.

3.a.  Since r=0.9891, the slope is 0.9891(SDy/SDx)=0.9891(24.95/66.33)
      =0.372 (rounded) and the intercept is ybar-0.372(xbar)=103-0.372(148)
      =47.937. Hence regression equation is:
                     time=47.937+0.372(size)
3.b.  For unit increase in size we can expect time to increase by 0.372
      time units. For a document of size zero units we can expect a
      processing time of 47.937 time units which may make sense since
      we would expect some overhead in processing an empty document.

4.a. H0: mu=$2.10; Ha: mu<$2.10
4.b. First, ybar=$2.04 is consistent. Assume H0 true and since n is
     large determine the z value. SD(ybar)=0.30/sqrt(36)=0.05 hence
     z=(2.04-2.10)/0.05=-1.2. The p-value is 11.505% (or 0.11505 
     expressed as a probability) which is non-significant and so we
     have insufficient evidence to reject the null hypothesis. The
     directors claim is therefore reasonable.
4.c. Since the null hypothesis was not rejected then the null hypothesis 
     mu=$2.10 is reasonable. Some other point estimate for the population
     mean would therefore be inappropriate.