The world's population went from 3 billion in 1960 to 6 billion in 2000. Suppose the world population continued to grow from 2000 on with a doubling time of 40 years. What would the population (in billions) be in 2030? Round to the nearest hundreth​

The mean finish time was 185.52 with a standard deviation of 0.327 minute. the winning car driven by chris finished in 185.13. the previous year race had a mean finish time of 110.3 with a standard deviation of 0.106. the winning car that year driven by karen finished in 110.13 minutes. find their respective z-scores. chris - z-score karen “- z-score