The National Retail Federation used data from a survey of 7439 adult Americans to estimate the percent who planned to spend more on holiday shopping in 2017 than they spent in 2016. They estimated that while 24% of adult Americans planned to spend more, for those age 16 to 24, the percentage was 46% (“Almost Half of Younger Consumers Plan to Spend More During the Holidays,” nrf.com/media/press-releases/almost-half-of-younger-consumers -plan-spend-more-during-the-holidays, retrieved February 5, 2018). Are the estimates given calculated using data from a sample or for the entire population?