What is a good science fair project for 7th grade. i really need ! btw, this is for a lot of points. btw, i put this in mathematics, but it is actually science. duh

An automated water dispenser fills packets with one liter of water on average, with a standard deviation of 5 milliliter. the manual says that after a year of operation the dispenser should be tested to see if it needs recalibration. a year later a number of filled packets are set aside and measured separately. it is found that the average packet now contains about 0.995 liters. does the dispenser need calibration? explain your answer.

Which expressions are equivalent to -7+3(-4e-3)? choose all answers that apply: choose all answers that apply: a -4(3e+4)? 4(3e+4) b 12e12e c none of the above

Julie was able to walk 16 km through the zoo in 6 hours. how long will it take her to walk 24 km through the zoo?