Variance is the average of the squared deviations from the arithmetic mean. The standard deviation is a square root from variance value. The standard deviation is a measure of the variability of values around the mean and is meant to be used with values that are normally distributed (e.g., follow a normal curve).
This integrated the seat belts and airbag into a restraint system, rather than the airbag being considered an alternative to the seat belt. In 1987, the Porsche 944 turbo became the first car to have driver and passenger airbags as standard equipment. The Porsche 944 and 944S had this as an available option. The same year also saw the first airbag in a Japanese car, the Honda Legend.
Considering that the last major innovation in luggage was a four-wheeled suitcase patented in 1972, itâs understandable that recent shifts have thrown the travel industry for a loop. For the past few years, makers of so-called smart luggageâthatâs bags with anything from a USB charging port to motorized wheelsâhave disrupted the market. Airlines are now taking note with arched brows: Earlier this month, American, Alaska, and Delta Airlines announced a ban on smart luggage with batteries that canât be removed. The restrictions, which take effect Jan. 15, 2018, apply to both checked and carry-on luggage. United and Southwest are expected to make similar announcements soon.