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 $8.35$ , find the range of pH values for the third reading that will result in the acidity level being normal.

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Payal Gupta | Contributor-Level 10

3 months ago

This is a short answer type question as classified in NCERT Exemplar

$\begin{array}{l} L e t t h e t h i r d p H v a l u e b e x . \\ G i v e n t h a t f i r s t p H v a l u e = 8.48 \\ a n d second p H v a l u e = 8.35 \\ ∴ A v e r a g e v a l u e o f p H = \frac{8.48 + 8.35 + x}{3} \\ B u t a v e r a g e v a l u e o f p H l i e s b e t w e e n 8.2 a n d 8.5 \\ ∴ 8.2 < \frac{8.48 + 8.35 + x}{3} < 8.5 \\ \Rightarrow 24.6 < 16.83 + x < 25.5 \\ \Rightarrow 24.6 - 16.83 < x < 25.5 - 16.83 \\ \Rightarrow 7.77 < x < 8.67 \\ H e n c e, t h e t h i r d p H v a l u e l i e s b e t w e e n 7.77 a n d 8.67 . \end{array}$

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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 $8.35$ , find the range of pH values for the third reading that will result in the acidity level being normal.

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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 . 4 8 and 8 . 3 5 , find the range of pH values for the third reading that will result in the acidity level being normal.

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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 $8.35$ , find the range of pH values for the third reading that will result in the acidity level being normal.