The table shows the amount of radioactive element remaining in a sample over a period of time. Radioactive Decay Rate
Amount of Radioactive Sample Time
(grams)
(hours)
186.0
0
147.0

7
117.0
14
93.0
21
23.3
63
Part 1: What is the half-life of the element? Explain how you determined this.
Part 2: How long would it take 320 g of the sample to decay to 2.5 grams? Show your work or explain your answer

Hannah is 3 years older than twice her brother joey’s age. joey is 2 years old. how old is hannah? show all of your work! the number of students is five more than seven times the number of teachers. there are 10 teachers. how many students are there? be sure to show all of your work!

Find the equation of the line that goes through the points (4, –1) and (2, –5). use slope formula,equation,to find the slope of a line that passes through the points. m = use slope-intercept form, y = mx + b, to find the y-intercept (b) of the line. b = write the equation in slope-intercept form, y = mx + b.

The management of a supermarket wants to adopt a new promotional policy of giving a free gift to every customer who spends more than a certain amount per visit at this supermarket. the expectation of the management is that after this promotional policy is advertised, the expenditures for all customers at this supermarket will be normally distributed with a mean of $95 and a standard deviation of $20. if the management wants to give free gifts to at most 10% of the customers, what should the amount be above which a customer would receive a free gift?