Answer:
-2
Step-by-step explanation:
Bc÷2a
5×-4÷2×5
-20÷10
-2
121 is big enough to assume normality and not worry about the t distribution. By the 68-95-99.7 rule a 95% confidence interval includes plus or minus two standard deviations. So 95% of the cars will be in the mph range

The question is a bit vague, but it seems we're being asked for the 95% confidence interval on the average of 121 cars. The 121 is a hint of course.
The standard deviation of the average is in general the standard deviation of the individual samples divided by the square root of n:

So repeating our experiment of taking the average 121 cars over and over, we expect 95% of the averages to be in the mph range

That's probably the answer they're looking for.
Answer: x = -1, -3
Step-by-step explanation:
The answer is Always true. because A is greater than B so put it this way if A=2 and B =1 then 2>1 same goes for C>D so if A+C would have to be greater than B+D for instance 2+2>1+1 or 4>2 so
<span>If A>B and C>D, then A+C>B+D Always true.
</span>
Answer:3 & 4
Step-by-step explanation: those are the two with multiplication/division