9514 1404 393
Answer:
1000
Step-by-step explanation:
If the number of protesters per minute remains a constant, then you could write the proportion ...
p/12 = 177/2.1
Multiplying by 12 gives ...
p = 12(177/2.1) ≈ 1011.4
Here, minutes are given to 2 significant figures, and the initial count is given to 3 significant figures. The best you can hope for is that your estimate is good to 3 significant figures:
1010 protesters
It is probably sufficient to report the number to 2 significant figures*:
1000 protesters
_____
* Unfortunately, with a number like 1000, the only way you can tell it has 2 significant figures is to report it as 1.0×10³ or 10. hundreds. The trailing zeros are usually not considered significant.
Answer:
203 ; 245
Step-by-step explanation:
158 + 45= 203
question 2
203+42= 245
Answer:
-37/6
Step-by-step explanation:
Memorize the definition of standard deviation: the sd is the square root of the average of the squared deviations of the mean. Wow. Let's do it.
Step 1. First we need the mean. That's easy. Add them up and divide by the count. Check if you get 16.88/5 = 2.81333.
Step 2. Now we're going to subtract this from each of the values, and square the result. Don't worry about negative signs, the squaring will get rid of those. Example for the first number:
(1 - 2.813)^2 = 3.29
The list of numbers I get is (rounded, in reality round as little as possible):
3.29, 2.60, 1.41, 2.35, 1.66, 6.18
Step 3: Add them all up. I get 17.49.
Step 4: Divide by the count of numbers. 17.49/6 = 2.91
Step 5: Take the square root from this result. SQRT(2.91) = 1.707305
TIP: Use excel to do all these steps, then run the set of numbers through Excel's built-in sd function (called STDEV.P) and see that you get the same result!
When you say "which," it sounds like it should be multiple choice. Anyways, here's the simplified form of
(When simplifying fractions, you should <em>never</em> have a square root on the bottom. Multiply by the square root to cancel it out)
