Is the confidence interval equivalent to the expression is it equivalent to the expression?

At school there are 526 students and 263 are girls about how likely is it that a randomly chosen student will be a boy

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.

60 2(x + 2) in the diagram, gef and hef are congruent. what is the value of x?