Two machines, X and Y, produce earbuds. Let X represent the diameter of an earbud produced by machine X, and let Y represent the diameter of an earbud produced by machine Y. X has a mean of 14 mm with a standard deviation of 0.6 mm, and Y has a mean of 15.2 mm with a standard deviation of 0.2 mm. Which answer choice correctly calculates and interprets the mean of the difference, D = X - Y?​

In the pendulum formula t=2pi. read the problem on the picture ! ; $; $; ! ; ! ; ! ; )$; ! ; ! ; ! ; $; $; $! ; ! ; ); $; $$

It is saturday morning and jeremy has discovered he has a leak coming from the water heater in his attic. since plumbers charge extra to come out on the weekends, jeremy is planning to use buckets to catch the dripping water. he places a bucket under the drip and steps outside to walk the dog. in half an hour the bucket is 1/5 of the way full. what is the rate at which the water is leaking per hour?

One number is 4 less than 3 times a second number. if 3 more than two times the first number is decreased by 2 times the second number, the result is 11. use the substitution method. what is the first number?