To make this job go faster and get you back on your board sooner, having the right tools at the ready is a must. The necessary items are listed below under Things You'll Need. In particular you'll need pliers/screwdriver, a socket wrench or ratchet and a skate tool (or T-tool). It's easy to lose or misplace a necessary nut, washer, or some other part when you're working on your board. To prevent this, consider putting the parts you're not working with inside a plastic bag. For each wheel removed, you should have a bolt and one to two bearing washers.
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One-sentence summary -- Gather the necessary materials. Store the removed parts in a safe place.

Q: The standard deviation is a measure of how spread out your data is. It gives you information on how similar each data point is within your sample, which helps you determine if the data is significant. At first glance, the equation may seem a bit complicated, but these steps will walk you through the process of the calculation. The formula is s = √∑((xi – µ)2/(N – 1)).  s is the standard deviation. ∑ indicates that you will sum all of the sample values collected. xi represents each individual value from your data. µ is the average (or mean) of your data for each group. N is the total sample number. To calculate the standard deviation, first you must take the average of the samples in the individual groups. The average is designated with the Greek letter mu or µ. To do this, simply add each sample together and then divide by the total number of samples.  For example, to find the average grade of the group that read the material before class, let’s look at some data. For simplicity, we will use a dataset of 5 points: 90, 91, 85, 83, and 94. Add all the samples together: 90 + 91 + 85 + 83 + 94 = 443. Divide the sum by the sample number, N = 5: 443/5 = 88.6. The average grade for this group is 88.6. The next part of the calculation involves the (xi – µ) portion of the equation. You will subtract each sample from the average just calculated. For our example you will end up with five subtractions.  (90 – 88.6), (91- 88.6), (85 – 88.6), (83 – 88.6), and (94 – 88.6). The calculated numbers are now 1.4, 2.4, -3.6, -5.6, and 5.4. Each of the new numbers you have just calculated will now be squared. This step will also take care of any negative signs. If you have a negative sign after this step or at the end of your calculation, you may have forgotten this step.  In our example, we are now working with 1.96, 5.76, 12.96, 31.36, and 29.16. Summing these squares together yields: 1.96 + 5.76 + 12.96 + 31.36 + 29.16 = 81.2. The formula divides by N – 1 because it is correcting for the fact that you haven’t counted an entire population; you are taking a sample of the population of all students to make an estimation.  Subtract: N – 1 = 5 – 1 = 4 Divide: 81.2/4 = 20.3 Once you have divided by the sample number minus one, take the square root of this final number. This is the last step in calculating the standard deviation. There are statistical programs that will do this calculation for you after inputting the raw data. For our example, the standard deviation of the final grades of students who read before class is: s =√20.3 = 4.51.
A: Define the formula for standard deviation. Average the samples in each group. Subtract each sample from the average. Square each of these numbers and add them together. Divide by the total sample number minus 1. Take the square root.

Article: In case you've decided to make changes to your lights after you've put up your tree, you should remove the lights for safety and ease of access. Anytime you need to replace a bulb in a strand of lights, you should always find a replacement bulb with the same voltage as the original. Look under the tag on the strand of lights to find voltage information. Some light strands blink because they have special bulbs that twinkle. If that's the case with your lights, you can get rid of the twinkle feature by switching out the bulbs. Oftentimes, the bulbs that blink on these strands will be marked with red or silver tips. However, if they aren't marked, plug in the strand, let it warm up, and use a small piece of masking tape to mark each blinking bulb. First, unplug the lights. Then, for each blinking bulb, hold the bulb by the base (where the light attaches to the strand) and pull out the bulb and the bottom casing. Remove the bulbs from the casing. If you have trouble removing the bulb and casing, use a screwdriver to pry the light out. For every blinking bulb that you removed, you want to replace it with a non-blinking bulb. Insert the new bulb into the case, making sure the two wires on the end go through the holes in the bottom of the case.  Fold the wires back so they rest against the side of the casing. When you have finished, reinsert the new bulb and casing back into the base. When you have replaced all the blinking bulbs and returned them all to their bases on the light strand, plug in the lights and test them. Give them a few minutes to warm up.
Question: What is a summary of what this article is about?
Remove the lights from the tree. Find replacement bulbs. Locate the blinking bulbs. Remove the bulbs. Replace the bulbs. Test the lights.

Article: Normally, glass etching involves the use a fairly powerful acid to cut or burn an image into glass. In this particular context, it will be used to burn off the exterior layer of the glasses. You will need:  A glass etching substance. A brand known as Armor Etch produces one popular variety of the material, but there are others as well.  High quality rubber gloves to protect your hands. Cotton swabs or some other material to use for applying the substance to the glasses. Do not rub the substance in, but merely apply it to the surface. Because of the strength of the acid in glass etching substances, you must work quickly. Only apply enough of the substance to cover the lens. Again, etching solution contains powerful acids. Over-exposure to these acids will likely damage the lenses. Use water to wash off the etching substance, unless the instructions call for alternatives. Wash thoroughly to guarantee that no residue from the substance remains. Use this to wipe and dry the lens, again using only side-to-side motions.
Question: What is a summary of what this article is about?
Purchase the necessary materials. Apply the glass etching substance using the cotton swabs. Let the substance remain on the lenses for no more than 5 minutes. Wash off the etching substance. Clean the glasses using a microfiber cloth.