Question

In: Statistics and Probability

The pH of a liquid is a measure of its acidity or alkalinity. Pure water was...

The pH of a liquid is a measure of its acidity or alkalinity. Pure water was a pH of 7, which is neutral. Solutions with a pH less than 7 are acidic while solutions with a pH greater than 7 are alkaline. A biologist was interested in testing the purity of lake water in Florida. A random sample of 59 lakes was taken, and the pH of water in each lake was recorded. The sample of lakes had an average pH of 6.729 with a standard deviation of 1.827.   

Using a significance level of 0.10, is there evidence the mean pH of Florida lakes is not neutral?

  • What hypotheses should be tested?

    Ho:μ=7Ho:μ=7
    Ha:μ<7Ha:μ<7

    Ho:μ≠7Ho:μ≠7
    Ha:μ=7Ha:μ=7

    Ho:μ=7Ho:μ=7
    Ha:μ>7Ha:μ>7

    Ho:μ=7Ho:μ=7
    Ha:μ≠7Ha:μ≠7

  • αα =  
  • Test Statistic: t =   (Note: round the t-score to two decimal places)
  • probability = Select an answer 0.8704 0.1296 0.2592   
  • decision: Select an answer Reject H₀ Fail to reject H₀
  • At the 0.10 level, there Select an answer is not is   significant evidence to conclude the mean pH in Florida lakes is Select an answer different than greater than less than  7.

Based on the decision of your test and the sample selected, what can you conclude?

  • The mean pH of Florida lakes is neutral.
  • The mean pH of Florida lakes is acidic.
  • The mean pH of Florida lakes is alkaline.

Solutions

Expert Solution

Let denotes the mean pH of Florida lakes.

There is not significant evidence to conclude the mean pH in Florida lakes is different than 7.

The mean pH of Florida lakes is neutral.


Related Solutions

Please answer all questions pH in Water: The acidity of alkalinity of a solution is measured...
Please answer all questions pH in Water: The acidity of alkalinity of a solution is measured using pH. A pH less than 7 is acidic; a pH greater than 7 is alkaline. The following data represent the pH in samples of bottled water and tap water. Tap 7.64 7.45 7.47 7.50 7.68 7.69 7.45 7.10 7.56 7.47 7.52 7.47 Bottled 5.15 5.09 5.26 5.20 5.02 5.23 5.28 5.26 5.13 5.26 5.21 5.24 a)Determine the mean, median and mode pH for...
Section 3.1 Measures of Central Tendency pH in Water: The acidity of alkalinity of a solution...
Section 3.1 Measures of Central Tendency pH in Water: The acidity of alkalinity of a solution is measured using pH. A pH less than 7 is acidic; a pH greater than 7 is alkaline. The following data represent the pH in samples of bottled water and tap water. Tap 7.64 7.45 7.47 7.50 7.68 7.69 7.45 7.10 7.56 7.47 7.52 7.47 Bottled 5.15 5.09 5.26 5.20 5.02 5.23 5.28 5.26 5.13 5.26 5.21 5.24 pH in Water: Use the same...
Fresh water from rivers and lakes varies in acidity/alkalinity depending on the rocks and soils it...
Fresh water from rivers and lakes varies in acidity/alkalinity depending on the rocks and soils it runs over. Granite country yields water that is slightly acidic, while water from limestone country is slightly alkaline. Acidity and alkalinity are measured on a pH scale, on which 7 is neutral, values below 7 are acidic and values above 7 are alkaline. pH can change due to pollution or due to waste from biomass such as algae. A certain river, fed by various...
For a certain wine, the mean pH (a measure of acidity) is supposed to be 3.39...
For a certain wine, the mean pH (a measure of acidity) is supposed to be 3.39 with a known standard deviation of σ = .13. The quality inspector examines 33 bottles at random to test whether the pH is too low, using a left-tailed test at α = 0.01. (a) What is the power of this test if the true mean is μ = 3.37? (Round your Z-value to 3 decimal places and final answer to 4 decimal places.) Power  ...
For a certain wine, the mean pH (a measure of acidity) is supposed to be 3.32...
For a certain wine, the mean pH (a measure of acidity) is supposed to be 3.32 with a known standard deviation of σ = .14. The quality inspector examines 31 bottles at random to test whether the pH is too low, using a left-tailed test at α = 0.05. (a) What is the power of this test if the true mean is μ = 3.30? (b) What is the power of this test if the true mean is μ =...
Explain why the pH scale is a convenient tool to measure the acidity or basicity of...
Explain why the pH scale is a convenient tool to measure the acidity or basicity of a substance. The definition for acids and bases provided in the introduction to this experiment is called theBronsted-Lowry formulation. Another formulation, that of Arrhenius, defines an acid as a speciesthat supplies H+ to solution and a base as something that supplies OH- to solution. Whichexplanation is more inclusive than the other, and why?
pH is a measure of acidity that winemakers must watch. A "healthy wine" should have a...
pH is a measure of acidity that winemakers must watch. A "healthy wine" should have a pH in the range 3.1 to 3.7. The target standard deviation is σ = 0.10 (i.e., σ2 = 0.01). The pH measurements for a sample of 16 bottles of wine are shown below. At α = .05 in a two-tailed test, is the sample variance either too high or too low?                         3.49   3.54   3.58   3.57   3.54   3.34  ...
IV. Comparing Buffering Capacity A. pH of Pure Water i. Measure out 30.0 mL DI H2O...
IV. Comparing Buffering Capacity A. pH of Pure Water i. Measure out 30.0 mL DI H2O into a beaker. 1. Calculate the expected pH of pure water.                        pH ________ 2. Measured pH of pure water.                                                 pH ___3.88______ 3. What is the percent error between the calculated and measured value? What are some of the possible sources of this error? % error __________ B. pH of Water and Strong Acid i. Measure out 30.0 mL DI H2O and 2.0...
A 50 mL sample of water has an initial pH of 11.2. Determine the total alkalinity...
A 50 mL sample of water has an initial pH of 11.2. Determine the total alkalinity and the different species of alkalinity if the equivalence point is reached at 8 mL of 0.01 N H2SO4 and 4.5 equivalence point is reached at 18 mL of 0.01 N H2SO4. (10 points
pH is a measure of proton activity and not concentration. (a) Calculate the pH of water...
pH is a measure of proton activity and not concentration. (a) Calculate the pH of water (T = 25o C) containing only 10-7 M H+ , i.e. in ultrapure water. (b) If the same water also contains 0.36 M NaCl, re-calculate the pH. Use the Debye-Huckel equation with A = 0.511 as an approximation to calculate the activity coefficient. (c) Explain the difference in pH.
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT