Estimating Defect Probability: SmileBright Electric Toothbrushes

To estimate the probability that a toothbrush is defective from a random sample of 317 new smile bright electric toothbrushes where 19 were defective, we can use the sample proportion as an estimate of the population proportion.

The sample proportion of defective toothbrushes is:

p̂ = 19 / 317 = 0.06

Therefore, we can estimate the probability that a toothbrush is defective to be around 0.06 or 6%.

This estimate is based on the assumption that the sample is representative of the entire population of smile bright electric toothbrushes, and that the sample size is large enough to provide a reliable estimate.