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The water acidity in a pool is considered normal when the average pH reading of three daily measurements is between ` 8.2 and 8.5` If the first two pH readings are `8.48 and 8.35`, then find the range of pH value for the third reading that will result in the acidity level being normal. |
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Answer» Given, first pH value = `8.48` and second pH value = `8.35` Let third pH value be x. Since, it is given that average pH value lies between ` 8.2 and 8.5` `:. 8.2 lt (8.48+8.35+x)/3 lt 8.5` `rArr 8.2 lt (16.83+x)/3 lt 8.5` `rArr 8 xx 8.2 lt 16.83 +x lt 8.5 xx 3` `rArr 24.6 lt 16.83 + x lt 25.5` `rArr 24.6 - 16.83 lt x lt 25.5 - 16. 83` `rArr 7.77 lt x lt 8.67` Thus, third pH value lies between ` 7.77 and 8.67` . |
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