Answer:
(115.2642, 222.7358).
Step-by-step explanation:
Given data:
type A: n_1=60, xbar_1=1827, s_1=168
type B: n_2=180, xbar_2=1658, s_2=225
n_1 = sample size 1, n_2= sample size 2
xbar_1, xbar_2 are mean life of sample 1 and 2 respectively. Similarly, s_1 and s_2 are standard deviation of 1,2. 
a=0.05, |Z(0.025)|=1.96 (from the  standard normal table)
So 95% CI is
(xbar_1 -xbar_2) ± Z×√[s1^2/n1 + s2^2/n2]
=(1827-1658) ± 1.96×sqrt(168^2/60 + 225^2/180)
= (115.2642, 222.7358).
 
        
             
        
        
        
Answer:
10
Step-by-step explanation:
it is 10 2000÷10=200
 
        
             
        
        
        
Answer:
(A) 509.78
We need to move the decimal point after the first non-zero digit
So,
=> 5.0978 × 10² (Since the decimal point is moved two places to the left)
(B) 0.0289
Again after the first non-zero digit:
So, it becomes:
=> 2.89 × 10⁻² (Since the decimal point is moved 2 places to the right so it will be negative also)
 
        
                    
             
        
        
        
Here we will tell you what 7 percent of 522 (7% of 522) is and then show you how we calculated it. The answer to "What is 7 percent of 522?" is:
36.54