You can obtain information about the mean population by taking a random sample of it and taking the average of that sample. The Law of big Numbers says that the bigger the sample, the more likely we will be closer to the real mean value. In other words, the margin of error is less likely to be big.
Answer:
1.861(10²)
Step-by-step explanation:
Proper scientific notation only has the ones place and decimals. To get the same value again, we would need the exponent to be 2 and not -2.
12 inches = 1foot
1yard = 3feet
6yards = 18feet
Rerange the question:
If edging cost $2.32 per 1foot stone, and you want a double layer of edging around your flower bed that is 18feet by 3feet. How much will edging you flower bed cost?
Perimter:
2(18+3)=42
And since you want to double it; double the perimeter too.
42(2)=84
2.32(84)=194.88
95% of red lights last between 2.5 and 3.5 minutes.
<u>Step-by-step explanation:</u>
In this case,
- The mean M is 3 and
- The standard deviation SD is given as 0.25
Assume the bell shaped graph of normal distribution,
The center of the graph is mean which is 3 minutes.
We move one space to the right side of mean ⇒ M + SD
⇒ 3+0.25 = 3.25 minutes.
Again we move one more space to the right of mean ⇒ M + 2SD
⇒ 3 + (0.25×2) = 3.5 minutes.
Similarly,
Move one space to the left side of mean ⇒ M - SD
⇒ 3-0.25 = 2.75 minutes.
Again we move one more space to the left of mean ⇒ M - 2SD
⇒ 3 - (0.25×2) =2.5 minutes.
The questions asks to approximately what percent of red lights last between 2.5 and 3.5 minutes.
Notice 2.5 and 3.5 fall within 2 standard deviations, and that 95% of the data is within 2 standard deviations. (Refer to bell-shaped graph)
Therefore, the percent of red lights that last between 2.5 and 3.5 minutes is 95%
