![seddy86](/avatars/4994.jpg)
seddy86
04.03.2020 •
Mathematics
Researchers have observed that rainforest areas next to clear-cuts (less than 100 meters away) have a reduced tree biomass compared to rainforest areas far from clear-cuts. To go further, Laurance et al. (1997) tested whether rainforest areas more distant from the clear-cuts were also affected. They compiled data on the biomass change after clear-cutting (in tons/hectare/year) for 36 rainforest areas between 100 m and several km from clear-cuts. The data are as follows:
-10.8, -4.9, -2.6, -1.6, -3, -6.2, -6.5, -9.2, -3.6, -1.8, -1, 0.2, 0.2, 0.1, -0.3, -1.4, -1.5, -0.8, 0.3, 0.6, 1, 1.2, 2.9, 3.5, 4.3, 4.7, 2.9, 2.8, 2.5, 1.7, 2.7, 1.2, 0.1, 1.3, 2.3, 0.5
Test whether there is a change in biomass of rainforest areas following clear-cutting.
Solved
Show answers
More tips
- S Style and Beauty How to Properly Apply Eye Makeup: Tips from a Professional Makeup Artist...
- A Animals and plants How ants survive winter: exploring the secrets of their winter life...
- F Food and Cooking Discover How to Properly Prepare Dough for Rasstegai...
- P Philosophy Unidentified Flying Object - What is the Nature of this Phenomenon?...
- F Family and Home Protect Your Home or Apartment from Pesky Ants...
- O Other What is a Disk Emulsifier and How Does it Work?...
- F Family and Home What does a newborn need?...
- F Family and Home Choosing the Right Car Seat for Your Child: Tips and Recommendations...
- F Food and Cooking How to Get Reconfirmation of Registration?...
- C Computers and Internet How to Get Rid of Spam in ICQ?...
Answers on questions: Mathematics
- M Mathematics Help ♂️♂️♂️♂️♂️♂️♀️♀️♀️♀️♀️♀️♀️♀️♀️♀️♀️♂️♂️♀️♀️♀️♂️♂️♂️♂️♂️...
- M Mathematics What is the equivalent fraction for 3 _ 8...
- M Mathematics Matthew invested $2,000 in a compound interest account for 3 years. The interest rate was 5%. How much money would it be in the end of third year in Mattew s account?...
- E English Who changed in The Outsiders in the movie?...
- M Mathematics A randomized telephone survey of adults in the United States determines that a certain number out of 504 respondents have one or more pets. They use p^ to construct a 95% confidence...
- E English One example in which people infer a meaning is ... (finish the sentence) please help T-T...
Ответ:
If we compare the p value and the significance level assumed
we see that
so we can conclude that we have enough evidence to FAIL to reject the null hypothesis, and we can conclude that we don't have a significant change at 5% of signficance.
Step-by-step explanation:
Data given and notation
-10.8, -4.9, -2.6, -1.6, -3, -6.2, -6.5, -9.2, -3.6, -1.8, -1, 0.2, 0.2, 0.1, -0.3, -1.4, -1.5, -0.8, 0.3, 0.6, 1, 1.2, 2.9, 3.5, 4.3, 4.7, 2.9, 2.8, 2.5, 1.7, 2.7, 1.2, 0.1, 1.3, 2.3, 0.5
We can calculate the mean and deviation with the following formulas:
And we obtain:
t would represent the statistic (variable of interest)
State the null and alternative hypotheses.
We need to conduct a hypothesis in order to check if there is a change in biomass of rainforest areas following clear-cutting, the system of hypothesis are :
Null hypothesis:
Alternative hypothesis:
Since we don't know the population deviation, is better apply a t test to compare the actual mean to the reference value, and the statistic is given by:
t-test: "Is used to compare group means. Is one of the most common tests and is used to determine if the mean is (higher, less or not equal) to an specified value".
Calculate the statistic
We can replace in formula (1) the info given like this:
P-value
First we need to calculate the degrees of freedom given by:
Since is a two tailed test the p value would be:
Conclusion
If we compare the p value and the significance level assumed
we see that
so we can conclude that we have enough evidence to FAIL to reject the null hypothesis, and we can conclude that we don't have a significant change at 5% of signficance.
Ответ:
x + 12
Step-by-step explanation: