Answer: -1.5
Step-by-step explanation:
When population standard deviation is known, then the formula to find the z-test statistic for population mean is given by :-

, where n= Sample size.
= Population mean
= Sample mean
= Population standard deviation.
As per given , we have
(average infants contracted typhoid each month)

n= 4 (No. of months)
Then , the value of the appropriate test statistic will be :




Hence, the value of the test statistic = -1.5
The answer would be the third one, p<319, because the auditorium can seat AT LEAST (<) 320 people, but it would be preferable to contain 319.
Answer:
Step-by-step explanation:
cant remember what this method is called but
change the second equation to be y = something
x + y = 10
y = -x + 10
plug in this y= in the first equation to get x
4x -2(-x + 10) = 4
4x + 2x -20 = 4
6x = 24
x = 4
then plug in the x we found into the original second equation
4 + y = 10
y = 6
so your ordered pair would be (4,6)
hope this helps <3