Research and development expenditures and sales of a large company

Data for Exercise 9.36 and Example 9.8

Randd

Format

A data frame/tibble with 12 observations on two variables

rd

research and development expenditures (in million dollars)

sales

sales (in million dollars)

References

Kitchens, L. J. (2003) Basic Statistics and Data Analysis. Pacific Grove, CA: Brooks/Cole, a division of Thomson Learning.

Examples

plot(sales ~ rd, data = Randd)
model <- lm(sales ~ rd, data = Randd)
abline(model, col = "purple")

summary(model)
#> 
#> Call:
#> lm(formula = sales ~ rd, data = Randd)
#> 
#> Residuals:
#>      Min       1Q   Median       3Q      Max 
#> -14.3800 -10.5291  -0.8083   7.5896  28.9340 
#> 
#> Coefficients:
#>             Estimate Std. Error t value Pr(>|t|)    
#> (Intercept)   55.008     10.126   5.433 0.000288 ***
#> rd            -6.816      2.626  -2.596 0.026690 *  
#> ---
#> Signif. codes:  0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1
#> 
#> Residual standard error: 12.95 on 10 degrees of freedom
#> Multiple R-squared:  0.4025,	Adjusted R-squared:  0.3428 
#> F-statistic: 6.737 on 1 and 10 DF,  p-value: 0.02669
#> 
plot(model, which = 1)

rm(model)