21,3 Abriol: Death Rates and Economic Factors 311 
For example, if it is stated that the mean age of death of persons 
dying in Baltimore is 39.83 + 2.60 years, it means that the mathematical 
probability that the true average age falls between 37.23 years 
(39.83 — 2.60) and 42.48 years (39.83 + 2.60) is exactly equal to the mathe- 
matical probability that the true age falls outside those limits. (7) 
The significance of our results, therefore, can be judged only 
after considering their relation to their probable errors. 
Bowly and Hooker(6) consider that when the correlation coef- 
ficient is six or more times the probable error it is practically 
certain that the two factors in question are associated; that is, 
the coefficient is significant. Raymond Pearl(7) considers a 
coefficient not significantly different from 0 when it is not more 
than four times its probable error. This basis of interpreting 
the probable error and coefficient will be considered as the crite- 
rion of significant results in this paper. 
ANALYSIS OF RESULTS 
The death rates from the diseases under consideration in 
the thirty-nine provinces are each correlated with the values 
of the personal property and real estate per capita, with taxes 
per capita, and with the average number of persons to a dwell- 
ing. Table 1 shows the means and the standard deviations of 
the factors entering into the correlation.. Table 2 shows 
the correlation coefficients. Casual examination of this table 
reveals a most interesting and rather surprising result, in as 
much as the coefficients are for the most part contrary to what 
was expected. For a closer scrutiny and analysis, each of the 
diseases is considered separately. 
TABLE 1.—Means and standard deviations of death rates from certain 
diseases and certain economic and housing factors. 
Variable. Mean. se ace 
SG Gr TESS Troi Bll COUSON 5. 65 fo. Sok hole ee ae 61.57 +2.63 | 24.38 +1.86 
PS Sg OE asa ap: Soa eel See Se eee op nace negra eee Se 17.19 £1.07 9.87 +0. 75 
WOMUMITIONE oe cee 2 hes wok van ccbenceusucateasesusdcuoceenncs 1.99 +0.35 8.28 40.25 
MEWUTNG COOLOER ics see, 22 sea ec re ws weigh eon 18.80 £1.45 | 13.40 +1.02 
Dpbentebires cei a ee ci es ork scart Gey Seen 2.55 +0.21 1.98 40.15 
SIODRORG bo csi ceka cache ceo nce pec cwalaea Lace lows ceas oe soca 0.01740. 002 | 0.01740. 001 
WOOTTON a aes Se ee 0.67 +£0.06 0.55 +0. 04 
Pulmonary fubdrcilobis: 2005 oe as 4.35 +0.26 2.42 +0.19 
Real O6t0te. 655 Gisecciceecc acd usenet tees ic al i a ek apap 78.24 +6.19 | 57.32 44.38 
ROG sick dood subs ancccucs bck wud uiinue sacs nkeee erie elenes 0.96 +0.07 0.68 +0. 05 
WMD Fe es re ee ee ee ae 4.70 +£0.06 0.52 +0. 04 
PU TELL. gipamncshimge Stag Gane nen gett nd GRMN US ey AI orgy Sats MERU peg 5.55 +0. 06 0.58 +0.04 
