Analyte Adj. R2 F p-value # Coefficients #
Sig.
CBCA 0.075 1.260 0.316 9 N/A
CBDA 0.246 2.052 0.087 9 N/A
CBNA 0.526 4.573 0.002 9 3
Phase 2 analysis (trimmed
data)
For phase 2 of the analysis, the <LOD substitution values and
all values that exceeded the 95% confidence interval upper limit
computed in the initial investigation were removed. The rationale here
was to determine if data would exhibit a more normalized distribution
once upper outliers and <LOQ values, which may have
contributed to the observed right-tailed skew, were deleted.
While oil density retained its normal distribution, the normality of
distribution for many of the analytes was noticeably improved from phase
1 (see Table 2). Histograms and Q-Q plots were constructed for oil
density, and each cannabinoid in the phase 2 data set, as shown in the
supplemental data addendum. The higher number of statistically normally
distributed analytes allowed for an increased number of regression tests
in phase 2.
The supplier and cultivar were coded into new dichotomous variables in
phase 2 using the same organization as conducted in phase 1 to
investigate the possible correlation between cannabinoid content
variation and suppliers and cultivars. Not all suppliers or cultivars
were included in the phase 2 regression analysis because some samples
were excluded as a result of trimming data at the 95% CI upper limit.
Linear regression analysis was conducted using the phase 2 (trimmed) and
coded supplier data. The supplemental data addendum shows the regression
model summaries, ANOVA tables, and coefficient tables for the phase 2
supplier regression tests. Many of the regression models for supplier
were significant and had a higher number of significant coefficients
than in phase 1. A summary of the supplier regression analysis with
suppliers is provided in Table 5.
Table
5: Phase 2 regression of analytes and suppliers