The present age of brother and sister are in the ratio 4 : 5. Three years ago, the ratio of their age was 3:4. Find their present age.​

The diameter of a circular chip is doubled to use in a new board game. the area of the new chip will be

Researchers were interested in whether relaxation training decreases the number of headaches a person experiences. they randomly assigned 20 participants to a control group or a relaxation training group and noted the change in number of headaches each group reported from the week before training to the week after training. which statistical analysis should be performed to answer the researchers' question?

Aboat costs 19200 and decreases in value by 12% per year. how much will it cost in 5 years