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Your Personal Tutor in Statistics. Click for Next. Calculating Areas Under the Normal Curve. Percentage Calculations. For example,. 50% is the same as 1/2. Click for Next. Click for Next. Click for Next. Calculating Percentages. We are all familiar with certain percentages. Why?.
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Your Personal Tutor in Statistics Click for Next Calculating Areas Under the Normal Curve Percentage Calculations
For example, 50% is the same as 1/2. Click for Next Click for Next Click for Next Calculating Percentages We are all familiar with certain percentages. Why? The word “per/cent” means “per hundred.” So 50% = 50/100 which equals 0.50, so 50% also equals 0.50. Don’t believe me? Put it in your calculator. Go ahead. OK, so 50% and 0.50 are exactly the same. Likewise, 38% and 0.38 are exactly the same. Going from % to decimal moves the decimal point 2 places to the LEFT. So…What is 55% as a decimal? = 0.55 . 55% = 55.% The leading zero is just a safety precaution to indicate that you just didn’t forget the leading digit.
Click for Next Calculating Percentages So remember it this way… DECIMAL PERCENT 0.34 34 % Move decimal 2 places to right DECIMAL PERCENT 0.34 34 % Move decimal 2 places to left
Click for Next Calculating Percentages Now to practice. Answer the question then click to see the answer. Convert 45% to decimal. 0.45 Convert 38.34% to decimal. 0.3834 Convert 0.005% to decimal. 0.00005 Convert 238.1% to decimal. 02.381 Let’s continue. Convert 0.45 to percent. 45% Convert 7.574 to percent. 757.4% Convert 0.005 to percent. 0.5% Convert .3875 to percent. 38.75%
Click for Next Click for Next Click for Next Calculating Percentages Using Percentages To take the percent of a number, convert the percent to a decimal and multiply. For example, A city with a population of 3.8 million people grew by 3.65%. How many people were added? Convert to decimal, 3.65% 0.0365 0.0365 x 3.8 = .1387 million people In another city the population decreased by 4%. If the initial population was 2.6 million, what was the population after the decrease? There is more than one way to do this problem. 1. You could convert 4% to decimal 0.04 and then multiply 0.04 x 2.6 = 0.104 million. Then the population is 2.6 – 0.104 = 2.496 . . . or . . . 2. If the population decreased by 4%, then it will become 96% of what it was initially. So 96% of 2.6 million is 0.96 x 2.6 = 2.496 million Ready to do some more problems?
Click for Next Calculating Percentages Using Percentages Now we will explore how percentages are used. Percentages are a way of comparing two numbers. For example, $50 $40 If a $50 item is reduced by $10, what is the percent change? The question really asks, “what was the change compared to the original price?” The change was -10 = -0.20 = -20% The original price was 50 So we have a change of -20%. If the price had gone up to $65, what would the percent change have been? The change is now 15 = 0.30 = 30% The original price was 50 So we have a change of 30%.