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!
Answer: 75 feet per hour
Step-by-step explanation:
X: 1, 3
Y: 200, 350
150/2
75
The result would be 3x^2+7x+2.
If you have any question, tell me and I would be more than happy to help! Thanks.
<h2>Question 9:</h2>
1. Use Pythagorean Theorem (a²+b²=c²) to solve for missing side of triangle and rectangle. x²+16²=20², or x²+256=400. So, x²=144, and x=12
2. Use formula: 1/2(h)(b1+b2). 1/2 (12) (30+14).
3. Simplify: 1/2 (12) (44)=1/2(528)=264
Area of whole figure is 264 square mm.
<h2>Question 10:</h2>
Literally same thing but with trigonometry.
1. Use sine to find out length of dotted line: sin(60°)=x/12
2: Simplify: 12*sin(60°)=x. x≈10.4 (rounded to the nearest tenth)
3. Use Pythagorean Theorem to find out last leg of triangle: 10.4²+x²=12²
4: Simplify: 108.16 +x²=144. x²=35.84 ≈ 6
5: Use formula: 1/2(h)(b1+b2). 1/2 (10.4) (30+36)
6: Simplify: 1/2 (10.4) (66) =343.2
7: Area of figure is about 343.2
Remember, this is an approximate answer with rounding, so it might not be what your teacher wants. The best thing to do is do it yourself again.