Answer is 3 1/10
6 1/2 - 3 2/5 =
13/2 - 17/5 =
65/10 - 34/10 =
31/10 = 3 1/10
Complete Question
A biologist reports a confidence interval of (3.5,4.9) when estimating the mean height (in centimeters) of a sample of seedlings. What is the estimated margin of error and the sample mean?
Answer:
The margin of error is 
The sample mean is 
Step-by-step explanation:
from the question we are told that
The upper limit is 
The lower limit is 
Generally the margin of error is mathematically represented as



Generally the sample mean is mathematically evaluated as

=> 
=> 
Answer:
2. I am pretty sure that it is right angles are congruent.
4. Angle O and R are congruent, never heard of their angles theorem but I think it might be related to CPCTC.
Step-by-step explanation:
Well a square is always used to represent a right angle so and both angle Q and N have squares and that should mean that they are both 90 degrees. Also while vertical angels are congruent, angles Q and N are not vertical from each other, Reflexive Property is if it is a side and not an angle I think.