Element X is a radioactive isotope such that its mass decreases by 81% every year. If an experiment starts out with 490 grams of Element X, write a function to represent the mass of the sample after tt years, where the daily rate of change can be found from a constant in the function. Round all coefficients in the function to four decimal places. Also, determine the percentage rate of change per day, to the nearest hundredth of a percent.

Do social recommendations increase ad effectiveness? a study of online video viewers compared viewers who arrived at an advertising video for a particular brand by following a social media recommendation link to viewers who arrived at the same video by web browsing. data were collected on whether the viewer could correctly recall the brand being advertised after seeing the video. the results are given below.correctly recalled the brandarrival 409153browsing20484b. conduct the hypothesis test, using the 0.025 level of significance.what is the value of the test statistic? χ2stat=what is the p-value? p-value=is this value significant atα=0.025?

Solve each equation using the quadratic formula. find the exact solutions. 6n^2 + 4n - 11

240 seventh graders and two-thirds of the students participate in after-school activities how many students participate in after-school activities