15 - 8
8 + 2 is 10, so there are 5 leftover. 2 + 5 is 7, so 8 + 7 is 15.
Working attached below. Hope this helps! Any questions let me know :)
Answer:
A) Yes
B) No
C) No
D) No
Step-by-step explanation:
A) Yes, every telephone number that could occur in that community will have an equal chance of being generated because the telephone numbers were generated randomly.
B) No, this method of generating telephone numbers would not result in a simple random sample (SRS) of local residences because the first three digits were generated in a different random way than the last four digits.
C) No, this method would not generate an SRS of local voters because not everybody will be pick up when they call because they may not be at home or they may be too busy to pick up.
D) No, this method is not unbiased in generating samples of households because there will be nonresponse bias since not everyone will pick up the call
For this case, the first thing we must do is define a variable.
We have then:
x: unknown number
We now write the equation that models the problem:
From here, we clear the value of x.
We multiply both sides of the equation by 2:
We subtract 30 on both sides of the equation:
Answer:
The value of the unknown number is given by:
