Question

et 001 Windows. Al BankCustomers may enter any one of three differentines that have formed at the teler windows. Answer the following questions Bank A 6.4 6.6 6.7 6.8 Bank B 54 5.9 62 72 7.1 8.8 7.5 72 7.5 7.9 79 8.6 7.9 10,0 Click the icon to view the table of Chi-Square critical values Construct a 95% confidence interval for the population standard deviation at Bank 0.40 m 105 min (Round to two decimal places as needed) Construct a 95% confidence interval for the population standard deviation of Bank 1.27 min un 3.38 min (Pound to two decimal places as needed) Interpret the results found in the previous parts. Do the confidence intervals suggest a difference in the variation among waiting times? Does the single-ine system of the multipleine system som to be a better rangement? OA The variation opears to be significantly lower with a single in wstom. The multiple newslem appears to be better OB. The variation spears to be significantly lower with a single in system. The single-line system appears to be better OC. The variation spears to be significantly lower with a multiple time system. The single-line system appears to be better OD. The variation spears to be significantly lower with a multiple-ine system. The multiple-line system appears to be better

Answer 1

Bank A:

Sample Size,   n=   10
Sample Standard Deviation,   s=   0.5754
Confidence Level,   CL=   0.95
      
      
Degrees of Freedom,   DF=n-1 =    9
alpha,   α=1-CL=   0.05
alpha/2 ,   α/2=   0.025
Lower Chi-Square Value=   χ²1-α/2 =   2.700
Upper Chi-Square Value=   χ²α/2 =   19.023

confidence interval for std dev is       
lower bound= √[(n-1)s²/χ²α/2] =   √(9*0.5754² / 19.0228)=   0.40
      
      
upper bound= √[(n-1)s²/χ²1-α/2] =   √(9*0.5754² / 2.7004)=   1.05
      

OB. The variation appears to be significantly lower with a single line system. The single-line system appears to be better

Please let me know in case of any doubt.

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Bank B:

Sample Size,   n=   10
Sample Standard Deviation,   s=   1.8394
Confidence Level,   CL=   0.95
      
      
Degrees of Freedom,   DF=n-1 =    9
alpha,   α=1-CL=   0.05
alpha/2 ,   α/2=   0.025
Lower Chi-Square Value=   χ²1-α/2 =   2.700
Upper Chi-Square Value=   χ²α/2 =   19.023

confidence interval for std dev is       
lower bound= √[(n-1)s²/χ²α/2] =   √(9*1.8394² / 19.0228)=   1.27
      
      
upper bound= √[(n-1)s²/χ²1-α/2] =   √(9*1.8394² / 2.7004)=   3.36