Data for Statistical Insight Chapter 1 and Exercise 5.110

Stamp

A data frame/tibble with 485 observations on one variable

- thickness
stamp thickness (in mm)

## Source

Izenman, A., Sommer, C. (1988), Philatelic Mixtures and Multimodal Densities,
*Journal of the American Statistical Association*, 83, 941-953.

## References

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

## Examples

hist(Stamp$thickness, freq = FALSE, col = "lightblue",
main = "", xlab = "stamp thickness (mm)")

lines(density(Stamp$thickness), col = "blue")

t.test(Stamp$thickness, conf.level = 0.99)

#>
#> One Sample t-test
#>
#> data: Stamp$thickness
#> t = 126.6, df = 484, p-value < 2.2e-16
#> alternative hypothesis: true mean is not equal to 0
#> 99 percent confidence interval:
#> 0.08426759 0.08778189
#> sample estimates:
#> mean of x
#> 0.08602474
#>