the amount of time a certain brand of light bulb lasts is normally distributed with a mean if 1800 hours and a standard deviation of 85 hours. Using the empirical rule, what percentage of light bulbs last between 1630 hours and 1970 hours?

Mary spent a total of $323.14 for a party.she spent a total of $200.22 on food,plus an additional $30.73 for each hour of the party.how long was the party?

Two corresponding sides of two similar triangles are 3cm and 5cm. the area of the first triangle is 12cm^2. what is the area of the second triangle?

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?