Answer:
Where is M??
Step-by-step explanation:
3x would have to be 15/2.
Since we have that 5x+3x=5x+15/2, the only pieces that are different are the 3x and the 15/2. This gives us the equation
3x=15/2
If we were to go on and solve this equation, we would multiply by 2, giving us
6x=15
Then we would divide by 6:
6x/6=15/6
and x=2.5.
To solve for the margin of error:
margin of error = critical value x standard error
To compute for the critical value:
1. compute alpha: α= 1 - (confidence level/100) = 1 - .99 = 0.01
2. Find the critical probability: p = 1 - α/2 = 1 - (0.01/2) = 0.995
3. Look for the z score at the z table, in this case it is 2.58. This is your critical value.
To compute for the standard error, the formula is:
standard error = standard deviation (σ) divided by √n = 1.6 / √420 = 0.0781
Now plug in the following in the formula:
margin of error: 2.58 * 0.0781 = 0.2014 or 0.20
The answer is letter C.
