The working life of a lightbulb is normally distributed with mean 1.3 years and standard deviation 0.3 year. What is the probability that it will last at least a year?

sample answer: you can determine whether each element of the domain is paired with exactly one element of the range. for example, if given a graph, you could use the vertical line test; if a vertical line intersects the graph more than once, then the relation that the graph represents is not a function.

one fourth of 9% = 2.25%

gavin is correct in saying : the equivalent quarterly interest rate would be

2.25%.

its kinda hard to answer this when we dont have all the information that we need.