Step-by-step explanation:
The solution to this problem is very much similar to your previous ones, already answered by Sqdancefan.
Given:
mean,  mu = 3550 lbs (hope I read the first five correctly, and it's not a six)
standard deviation, sigma = 870 lbs
weights are normally distributed, and assume large samples.
Probability to be estimated between W1=2800 and W2=4500 lbs.
Solution:
We calculate Z-scores for each of the limits in order to estimate probabilities from tables.
For W1 (lower limit), 
Z1=(W1-mu)/sigma = (2800 - 3550)/870 = -.862069
From tables, P(Z<Z1) = 0.194325
For W2 (upper limit):
Z2=(W2-mu)/sigma = (4500-3550)/879 = 1.091954
From tables, P(Z<Z2) = 0.862573
Therefore probability that weight is between W1 and W2 is
P( W1 < W < W2 )
= P(Z1 < Z < Z2) 
= P(Z<Z2) - P(Z<Z1)
= 0.862573 - 0.194325
= 0.668248
= 0.67 (to the hundredth)
 
        
             
        
        
        
It would be negative 5 since it is going down.
        
             
        
        
        
Answer:
B. y = 1.3 + 2
Step-by-step explanation:
The slope is positive, and the y intercept is at positive 2.
 
        
             
        
        
        
Answer:
26
Step-by-step explanation:
5 × 4 = 20 (rectangle)
8-5 = 3 (triangle)
3×4÷2 = 6
20+6 = 26
 
        
             
        
        
        
Remember, the slope formula is y2-y1 over x2-x1. To plug numbers into the formula, find two points. Then, you substitute the points into the formula.