Which of the following are examples of exponential decay?
- the population of a florida is increasing by 43% each year.
- the pesticide ddt has a half-life of 15 years.
- march madness has 64 teams in the bracket. each round, half the teams are eliminated.
- after an antibiotic is added to a culture of bacteria, the number of bacteria is reduced by half every three hours.
- a tree frog population doubles every three weeks.

What is the value of x in the equation 2(x-4) = 4(2x + 1)?

Which of the following is the graph of y= square root -x-3

(20 points) a bank has been receiving complaints from real estate agents that their customers have been waiting too long for mortgage confirmations. the bank prides itself on its mortgage application process and decides to investigate the claims. the bank manager takes a random sample of 20 customers whose mortgage applications have been processed in the last 6 months and finds the following wait times (in days): 5, 7, 22, 4, 12, 9, 9, 14, 3, 6, 5, 15, 10, 17, 12, 10, 9, 4, 10, 13 assume that the random variable x measures the number of days a customer waits for mortgage processing at this bank, and assume that x is normally distributed. 2a. find the sample mean of this data (x ě…). 2b. find the sample variance of x. find the variance of x ě…. for (c), (d), and (e), use the appropriate t-distribution 2c. find the 90% confidence interval for the population mean (îľ). 2d. test the hypothesis that îľ is equal to 7 at the 95% confidence level. (should you do a one-tailed or two-tailed test here? ) 2e. what is the approximate p-value of this hypothesis?