Microplastics have been found in both tap water and bottledwater.
Bottled water results A study analyzed 259 bottlesand found an average of 320 plastic particles for every liter ofwater being sold. The associated standard deviation was 327. (Yes,the standard deviation is larger than the mean.)
Tap water results In a similar study, 30 tap watersamples were analyzed. The average number of plastic particlesfound in each liter in the United States was 8.8 with a standarddeviation of 2.3.
Conduct a hypothesis to evaluate if there is a difference betweenthe average number of plastic particles in water bottles vs tapwater.
What type of test should be run?
- Paired T-test
- 2 Sample T-test
- T-test
- 1 Proportion Z-test
- 2 Proportion Z-test
What are the hypotheses for this test?
- Ho: μbottled = μtap
Ha: μbottled > μtap - Ho: μbottled = μtap
Ha: μbottled < μtap - Ho: μbottled = μtap
Ha: μbottled ≠μtap
The test statistic for the hypothesis testis:Â Â (please round to two decimal places)
The p-value for the hypothesis test is:Â Â (pleaseround to four decimal places)
Interpret the result of the hypothesis test in the context of thestudy:
- We reject the claim that the average number of plasticparticles found in tap water and bottled water is the same.
- We fail to reject the claim that the average number of plasticparticles found in tap water and bottled water is the same.
