The percentiles indicate the age by which a percentage of the population is expected to fail. Use the percentile values to determine whether your product meets reliability requirements, or to compare the reliability for two or more designs of a product.
Use these values only when the distribution fits the data adequately. If the distribution does not fit the data well, these estimates may not be accurate. Use the distribution ID plot, probability plot, and goodness-of-fit measures to determine whether the distribution adequately fits the data.
For the engine windings data, at a temperature of 80° C, approximately 1% of the engine windings will fail at 19.3281 hours.