Answer: D. The number of phone calls made daily from an office
Explanation: A continuous random variable is defined as a variable where the data can have an infinite number of possibilities.
Let's check the given options: 1- Option A: The number of employees in an office is fixed. It will not change from one day to another. Therefore, the variable does not have infinite possibilities ............> This option is incorrect
2- Option B: The salaries of employees in an office are fixed. They will not change from one day to another. Therefore, the variable does not have infinite possibilities ............> This option is incorrect
3- Option C: The number of printers in an office is fixed. It will not change from one day to another. Therefore, the variable does not have infinite possibilities ............> This option is incorrect
4- Option D: The number of phone calls made daily from an office is not fixed. They could be any number and can change daily. Therefore, the variable has infinite possibilities ............> This option is correct
If it has 79 protons it will have a total proton charge of 79 so tho make the charge zero we need to add (79) electrons .Mathematically (1*79)+(-1*79)=0
