![subject](/tpl/images/cats/mat.png)
Mathematics, 18.03.2021 01:20 cvrlxzzz6507
An ecologist is examining whether the number of fish caught in a large river basin has changed since a fire burned some of the surrounding forested area and vegetation along the river. Data in the form of fishing reports was available for a five-year period before the fire. From a random sample of 195 fishing reports before the fire, the mean catch was 6.3 fish with a standard deviation of 1.6. In a random sample of 143 reports three years after the fire, the mean catch was 7.1 fish with a standard deviation of 2.1. Which of the following represents the standard error of the difference in the mean number of fish caught before and after the fire?
A. √1.6/ 2.1 + 195 /143
B. √2.12 + 143
C. √1.62/ 2.12 + 195 /143 195
D. √1.62/ 2.12 +1195 /1143
E. √1.62 /195 +2.12 /143
![ansver](/tpl/images/cats/User.png)
Answers: 2
Another question on Mathematics
![question](/tpl/images/cats/mat.png)
Mathematics, 21.06.2019 16:10
Abox contains 1 plain pencil and 4 pens. a second box contains 5 color pencils and 5 crayons. one item from each box is chosen at random. what is the probability that a plain pencil from the first box and a color pencil from the second box are selected? write your answer as a fraction in simplest form.
Answers: 1
![question](/tpl/images/cats/mat.png)
![question](/tpl/images/cats/mat.png)
Mathematics, 22.06.2019 00:30
Hi i’m not sure how to do question 20 if u could explain how to do it that’d b great
Answers: 1
![question](/tpl/images/cats/mat.png)
Mathematics, 22.06.2019 00:30
Given abc find the values of x and y. in your final answer, include all of your calculations.
Answers: 1
You know the right answer?
An ecologist is examining whether the number of fish caught in a large river basin has changed since...
Questions
![question](/tpl/images/cats/istoriya.png)
History, 12.11.2020 20:40
![question](/tpl/images/cats/mat.png)
Mathematics, 12.11.2020 20:40
![question](/tpl/images/cats/mat.png)
![question](/tpl/images/cats/mat.png)
Mathematics, 12.11.2020 20:40
![question](/tpl/images/cats/en.png)
![question](/tpl/images/cats/health.png)
![question](/tpl/images/cats/istoriya.png)
![question](/tpl/images/cats/mat.png)
Mathematics, 12.11.2020 20:40
![question](/tpl/images/cats/mat.png)
Mathematics, 12.11.2020 20:40
![question](/tpl/images/cats/mat.png)
![question](/tpl/images/cats/mat.png)
![question](/tpl/images/cats/biologiya.png)
![question](/tpl/images/cats/mat.png)
Mathematics, 12.11.2020 20:40
![question](/tpl/images/cats/himiya.png)
Chemistry, 12.11.2020 20:40
![question](/tpl/images/cats/User.png)
Engineering, 12.11.2020 20:40
![question](/tpl/images/cats/mat.png)
Mathematics, 12.11.2020 20:40
![question](/tpl/images/cats/mat.png)
![question](/tpl/images/cats/en.png)
![question](/tpl/images/cats/mat.png)
Mathematics, 12.11.2020 20:40