163
• Vol. XI, Núm. 3 • Septiembre-Diciembre 2017 •
values of the mean, standard deviation, median,
minimum and maximum values, range, skewness and
kurtosis corresponding to the mean annual, mean
minimum and mean maximum annual temperatures.
For example, by analyzing Table 2, which depicts the
descriptive statistics for the mean annual tempera-
tures, the values of the mean and the median are almost
identical. Moreover, the relation between the mean
annual value of 70.243 and the value of standard
deviation of 0.8909 are very different. Likewise, the
values of the skewness and kurtosis are very close to
zero. These observations preclude the possibility of
experimental errors that could degrade the
trustworthiness of the pursued results. Similarly, by
analyzing the results of Table 2a, the mean maximum
value is almost the same as the median value. Too, the
skewness value is close to zero. Also the value of the
kurtosis of -0.1844 suggests a platikurtic (flat)
distribution probably attributed to the extreme value
of 83.6 oF. F o r t h e sa me r e a so n, th e res u l ts of T a b le 2 b
show more symmetric values as Table 2. From the
experimental design standpoint, all these observations
suggest a good symmetry of the distributions of the
te mp e ratu re s a nd t he a bs en c e o f se ri o us ex pe r im e nta l
errors that could compromise the predictive
capability of the statistical models of this research.
Insofar as the screening process to select the best
continuous probability distribution for the mean
annual temperatures, the results showed the normal
probability function, as the best one. This is shown in
Figure 2 with an A-D equal to 0.315 and a P value of
0.539. Likewise, Figure 3 shows the normal
probability plot corresponding to the mean annual
maximum temperatures, with an A-D value of 0.283
and a P value of 0.630. Equally, Figure 4 shows the
normal probability plot of the mean minimum annual
temperature values. In this graph the ensuing
goodness of fit test of the Anderson-Darling values of
0.285 and the P-value of 0.623 were the lowest values
recorded, after testing several continuous probability
distributions, as the lognormal, Weibull, Gamma, etc.
Besides, the usefulness of the normal probability
graphs is that these graphs are useful to calculate any
probability (by interpolation) associated with any
tem pe ra tu re , w it h a g oo d de gre e of p re cis io n.
Insofar as the results of the calculations of the
cumulative and density probabilities, Figures 5, 6 and
7 show the results. For example, Figure 5 shows the
graphs of the cumulative and density probabilities
for the mean annual temperatures. By analyzing the
density probability curve, the symmetry is almost
perfect; conditions that exclude experimental errors.
Similarly, Figure 6 shows the cumulative and density
probabilities for the mean annual maximum
temperatures. By analyzing the right-hand density
probability curve, it is a little skewed to the right due
to the extreme value of 83.6, which occurred in 1990.
Inasmuch as, Figure 7 which shows the cumulative
and density probabilities for the mean annual
minimum temperatures, it is seen that the symmetry
of these values is almost perfect barring the existence
of experimental errors that could degrade de
outcomes.
About the results related to the construction of
the probability plotting positions, these graphs are
useful to calculate periods of return and their
associated probabilities of occurrence. These
probability-plotting positions are displayed in Figures
8, 9 and 10. For example, Figure 8 shows the normal
probability plotting position for the mean annual
tem pe ra tu re s, w it h th ei r r es pe ct iv e pe ri ods o f re tu rn
and probabilities of occurrence. Likewise, Figure 9
shows the normal probability plotting position for
the mean minimum annual temperatures, with their
respective periods of return and probabilities of
occurrence. Lastly, Figure 10 shows the normal
probability plotting position for the mean maximum
annual temperatures. These graphs can be used to
calculate any desired temperature and its associated
period of return and probability of occurrence. For
example, by analyzing Figure 8, if it is desired to
calculate a period of return for a mean annual
temperature of 71 oF, its corresponding period of
return is about 5 years, with a probability of
occurrence of .2 and so on. Similarly, with Figure 9, if
it is desired to calculate a mean minimum value of 62
oF, its cor r e s p o n d i n g p er i o d o f r e tu r n i s 1 0 0 y e a r s a n d
the probability of occurrence is 0.01 and so on. Alike,
with Figure 10, if it is desired to calculate a mean
maximum annual temperature of 83 oF, i ts p er i od o f
return is 100 years and its associated probability
would be .01 and so on.
HECTOR QUEVEDO-URIAS, FELIPE ADRIÁN VÁZQUEZ-GÁLVEZ, ERNESTOR ESPARZA, OSCAR IBAÑEZ Y TULIO SERVIO DE LA CRUZ: Statistical model for
the analysis of temperature: case study the 1895 - 2014 serie for Florida state