-15+7=-8
Adding numbers with different signs makes it subtraction and the answer will have the sign of the bigger number
To calculate the z-statistic, we must first calculate the
standard error.
Standard error is standard deviation divided by the square
root of the population. In this case, it is equal to 2.68.
The z-score is defined the distance from the sample to the
population mean in units of standard error.
z = (195 – 208)/2.68 = -4.86
To get the answer we can use proportion.
30----------100%
12-----------x
Cross multiply now
30x=12*100%
30x=1200% /:30 (divide both sides by 30)
x=40% - it's the percentage of cars which finished the race.
100%-40%=60% - it's the answer
Answer: I think the answer would be (2, -1)
The forth picture is the one that represents 4.5
