One hundred grams of radium are stored in a container. the amount r of radium present after t years can modeled by r=10e^-0.00043t. after how many years will only 5 grams of radium be present? round your answer to the nearest whole year.

Asurvey of 45 teens found that they spent an average of 25.6 hours per week in front of a screen (television, computer, tablet, phone, based on the survey’s sample mean, which value could be the population mean? 2.3 hours 27.4 hours 75.3 hours 41.5 hours