log using SOCY602-Kleinbaum-Problems-CH3.txt, replace text

/* 
    3a. P(Z GE -1)=?               3b. P(Z LE ?)=0.20
*/
di 1- normal(-1)
di invnormal(.2)


/*
    4a. P(chi2; 7df GE ?)=0.01     4b. P(chi2; 12df LE 14)=?
*/
di invchi2tail(7,.01)
di chi2tail(12,14)
di 1-chi2(12, 14)


/*
    5a. P(t; 13df GE ?)=0.10       5b. P(chi2; 28df GE 2.05)=?
*/
di invttail(13,.1)
di ttail(28,2.05)


/*
    6a. P(F 6,24f GE ?)=0.05       6b. P(F 5,40df GE 2.9)=?
*/
di invFtail(6,24,.05)
di Ftail(5,40,2.9)


/* 
    9. Find the mean, median, variance, and z-scores
*/
capture clear
input y
0 
2 
5 
6 
3 
3 
3 
1 
4 
3 
end
tabstat y, statistics(mean p50 variance) format(%5.1f)
egen zy=std(y)
format zy %5.3f
list, separator(2) divider noobs
capture clear


/*
   11a. Given y-bar=190, var=100, and n=25 what is PZ>?)
*/
local mean=190
local se=(100^.5)/(25^.5)
local t=(180-190)/`se'
di `t'
di 1-ttail(24,`t')

/*
   11b. Find CL0.8
*/
local ub=`mean'+(invttail(24,.1)*`se')
local lb=`mean'+(invttail(24,.9)*`se')
di "lb= " `lb' "   ""ub= " `ub'
di (`lb'-190)/`se'
di ttail(25,((`ub'-190)/`se'))
di (`ub'-190)/`se'
di ttail(25,((`lb'-190)/`se'))


/*
   13.  n=32, diff=30, sd=11.  Calculate CI99
*/
cii 32 30 11, level(99)


/*
   14. Calculate se
*/
quietly {
  ttesti 15 111.6 9.5 19 100.9 11.5
  noisily di _n "Chapter 3, problem 14
  noisily di _col(2) "The standard error of the difference of the mean=" %5.3f `r(se)'
}



/*
   15. t-test
*/
capture clear
input group bw
0 132
0 145
0 124
0 122
0 165
0 144
0 151
1 141
1 139
1 172
1 131
1 150
1 125
end
ttest bw, by(group)
capture clear

log close