> fm1 <- lm(ascorbic ~ pct.dry + cultB.id + cultC.id,data=lima)
> summary(fm1)
Coefficients: Estimate Std. Error t value Pr(>|t|)
(Intercept) 213.2 16.3 13.1 4.64e-08 ***
pct.dry   -3.9 0.43 -9.1 1.96e-06 ***
cultB.id -6.2 5.53 -1.1 0.290
cultC.id   20.5 5.42 3.8 0.003 **
Signif. codes: 0 *** 0.001 ** 0.01 * 0.05 . 0.1 1
Residual standard error: -- intentionally omitted -MultipleR-squared: 0.91, Adjusted R-squared: 0.88 F-statistic: 36.84 on 3and 11 DF, p-value: 4.956e-06
(c) Determine whether each of the statements below is supportedby the multiple regression model above. If the statement issupported, circle “yesâ€. If the statement is not supported, circle“noâ€.
YES NO (i) After controlling for differences among the cultivars,there is strong evidence that ascorbic acid content decreases aspercent dry weight increases.
YES NO (ii) The estimate of the intercept suggests that lima beanplans of cultivar A have an average ascorbic acid content of213.
YES NO (iii) After accounting for the effect of percent dry weight,there is strong evidence that the ascorbic acid content of cultivarB is less than the ascorbic acid content of cultivar A.
YES NO (iv) After accounting for the effect of percent dry weight,there is strong evidence that the ascorbic acid content of cultivarC is less than the ascorbic acid content of cultivar A.
