Answer:
9b+1
Step-by-step explanation:
combine like terms
7b-1b+3b=9b
 
        
                    
             
        
        
        
Answer:
68% of the sample can be expected to fall between 28 and 32 cm
Step-by-step explanation:
The Empirical Rule states that, for a normally distributed random variable:
68% of the measures are within 1 standard deviation of the mean.
95% of the measures are within 2 standard deviation of the mean.
99.7% of the measures are within 3 standard deviations of the mean.
In this problem, we have that:
Mean = 30
Standard deviation = 2
What proportion of the sample can be expected to fall between 28 and 32 cm
28 = 30-2
28 is one standard deviation below the mean
32 = 30 + 2
32 is one standard deviation above the mean
By the Empirical Rule, 68% of the sample can be expected to fall between 28 and 32 cm
 
        
             
        
        
        
Red has a greater value. 
Blue = -2
Red = 3
        
             
        
        
        
Answer:
108
Step-by-step explanation:
The n th term of an arithmetic sequence is
 = a₁ + (n - 1)d
 = a₁ + (n - 1)d
where a₁ is the first term and d the common difference
Here a₁ = 12 and d = 16 - 12 = 4, thus
 = 12 + (24 × 4) = 12 + 96 = 108
 = 12 + (24 × 4) = 12 + 96 = 108