The train is traveling at 165 mph
495/3=165
825/5=165
1155/7=165
1485/9=165
Answer:
22
Step-by-step explanation:
add everything in the parentheses first, then multiply by 1/2 (or divide by 2)
(28 + 7 + 6 + 3) x 1/2 = 44 x 1/2 = 22
Answer:
(Q) Find the amount in the account at the end of 1 year.
(A) $8,190
2.
(Q) Find the amount in the account at the end of 2 years.
(A) $16,380
I have an expression

floating around in my head; let's see if it makes sense.
The variance of binary valued random variable b that comes up 1 with probability p (so has mean p) is

That's for an individual sample. For the observed average we divide by n, and for the standard deviation we take the square root:

Plugging in the numbers,

One standard deviation of the average is almost 2% so a 27% outcome was 3/1.9 = 1.6 standard deviations from the mean, corresponding to a two sided probability of a bit bigger than 10% of happening by chance.
So this is borderline suspect; most surveys will include a two sigma margin of error, say plus or minus 4 percent here, and the results were within those bounds.