trigonometry cosine law: A radar station at point A is tracking two ships. Ship B is 4.5 km away in a direction 42degrees east of north. Ship C is 3.3 km away in a direction 58degrees west of north. How far apart are the two ships, to the nearest tenth of a kilometre?

In a survey of 1015 adults, a polling agency asked, "when you retire, do you think you will have enough money to live comfortably or not. of the 1015 surveyed, 534 stated that they were worried about having enough money to live comfortably in retirement. construct a 90% confidence interval for the proportion of adults who are worried about having enough money to live comfortably in retirement.