Question: the fortran program of calculating the fibonacci numbers is shown...
Question details
The FORTRAN program of calculating the Fibonacci numbers is shown below [1]:
PROGRAM fbnc 

c 
Fibonacci sequence 
integer f1,f2,f3 

f1=1 □ 

f2=1 □ 

write(*,*)'To display Fibonacci numbers.' □ 

write(*,*)'Enter the number of terms to be displayed:' □ 

read(*,*)n □ 

write(*,*)'The Fibonacci sequence is : ' □ 

IF(n.EQ.1)THEN □ 

write(*,10)f1 □ 

10 
format(1x,I6) 
ELSE □ 

write(*,10)f1 □ 

write(*,10)f2 □ 

DO 20 i=3,n □ 

f3=f1+f2 □ 

write(*,10)f3 □ 

f1=f2 □ 

f2=f3 □ 

20 
continue □ 
ENDIF □ 

STOP □ 

END □ 
 Identify all operators (including the EndOfStatement EOS operators, □) and their frequencies. Put operator’s names and their frequency values in Table 1below:
TABLE 1: Operators and their Frequencies
No. 
Operator 
Frequency, f1 
Based on this data (from Table 1), estimate total number of unique operators, n1, and the total number of operators appearance, N1:
n1 =
N1 = SUM(f1) =
 Identify all operands and their frequencies. Put operand’s names and their frequency values in Table 2 below:
TABLE 2: Operands and their Frequencies
No. 
Operand 
Frequency, f2 
Based on this data (from Table 2), estimate total number of unique operands, n2, and the total number of operands appearance, N2:
n2 =
N2 = SUM(f2) =
 Following the Halstead’s metrics definitions [23], estimate the following metrics:
The program length (N): N = N1 + N2
The vocabulary size (n): n = n1 + n2
The program volume (V): V = N * log_{2}(n)
The difficulty level or error proneness (D) of the program: D = ( n1 / 2 ) * ( N2 / n2 )
The program level (L): L = 1 / D
The effort to implement (E) or understand a program: E = V * D
The time to implement or understand a program (T): T = E / 18
The number of delivered bugs (B): B = ( E^(2/3) ) / 3000
(here the symbol ^ stands for "to the
exponent")
 Make comments on estimates of implementation of this algorithm in any other programming language that you are familiar with.