The given number arranged in order are: 9, 9, 10, 10, 12, 12, 14, 15, 15, 15, 17 1. To find the mean, add all the number together and divide the summation by 11[ which is the total number of the figures given] Mean = [9 + 9 + 10 + 10 + 12 + 12 + 14+ 15 + 15 + 15 + 17] / 11 = 138 / 11 Mean = 12.5 Therefore, the mean is approximately equal to 13.
2. The median of a number refers to the number in the middle of a sorted set of number. To find the median of a set of numbers, the numbers have to be arranged first in the correct increasing order and the number that falls in the middle will be the median. If two numbers fall in the middle, add the two together and find the average. For the set of number given above, the number that falls in the middle is 12. Therefore, the median = 12.
3. The mode of a set of number refers to the number in the set, which has the highest frequency of occurrence, that is, it is the number that occur most. Looking at the set of number given above, 15 occurred three different times. Therefore, the mode of the set of number given above is 15. Mode = 15.
4. The range of a set of number refers to the difference between the highest and the lowest numbers in the set of a given number. It represents the spread of the data. In the set of numbers given above the range is determined thus: Range = 17 - 9 = 8. Therefore, Range = 8.
2 moles of iron (Fe) react with 1 mole of molecular oxygen (O₂) to produce 2 moles of iron oxide (FeO). The ratio of Fe to FeO is 1-to-1, so if one starts with 42.4 mol of Fe, one will end up with the same amount of FeO, 42.4 mol.
Look up the molar mass of Fe and O:
• Fe = 55.845 g/mol
• O = 15.999 g/mol
Then the molar mass of FeO is approximately 71.835 g/mol, and so the mass of 42.4 mol of FeO is