Williams Exhibit No. 7.xls

Sheet3
Sheet2
Sheet1
Indicative Forward PCRB Variable Rates
Floating Rate PCRBs
PCRB / LIBOR
(a)
(b)
(b)/(a)
* Source: Bloomberg L.P.
Average
(1)
(2)
(1) * (2)
LIBOR*
Forward 30 Day
Historical Floating
Rate PCRB / 30
Day LIBOR
Forecast
Floating
Rate PCRB
30 Day LIBOR
Idaho Rate Case
For September 30, 2005
?10?/?1?/?1998
0.05
0.03
0.63
?11?/?1?/?1998
0.05
0.03
0.60
?12?/?1?/?1998
0.06
0.03
0.59
?1?/?1?/?1999
0.05
0.03
0.56
?2?/?1?/?1999
0.05
0.03
0.54
?3?/?1?/?1999
0.05
0.03
0.59
?4?/?1?/?1999
0.05
0.03
0.62
?5?/?1?/?1999
0.05
0.03
0.66
?6?/?1?/?1999
0.05
0.03
0.67
?7?/?1?/?1999
0.05
0.03
0.58
?8?/?1?/?1999
0.05
0.03
0.59
?9?/?1?/?1999
0.05
0.03
0.65
?10?/?1?/?1999
0.05
0.03
0.63
?11?/?1?/?1999
0.06
0.03
0.61
?12?/?1?/?1999
0.06
0.04
0.59
?1?/?1?/?2000
0.06
0.03
0.56
?2?/?1?/?2000
0.06
0.04
0.62
?3?/?1?/?2000
0.06
0.04
0.61
?4?/?1?/?2000
0.06
0.04
0.64
?5?/?1?/?2000
0.07
0.05
0.75
?6?/?1?/?2000
0.07
0.04
0.66
?7?/?1?/?2000
0.07
0.04
0.57
?8?/?1?/?2000
0.07
0.04
0.62
?9?/?1?/?2000
0.07
0.05
0.68
?10?/?1?/?2000
0.07
0.04
0.64
?11?/?1?/?2000
0.07
0.04
0.66
?12?/?1?/?2000
0.07
0.04
0.62
?1?/?1?/?2001
0.06
0.03
0.52
?2?/?1?/?2001
0.06
0.04
0.67
?3?/?1?/?2001
0.05
0.03
0.64
?4?/?1?/?2001
0.05
0.04
0.80
?5?/?1?/?2001
0.04
0.03
0.84
?6?/?1?/?2001
0.04
0.03
0.80
?7?/?1?/?2001
0.04
0.03
0.72
?8?/?1?/?2001
0.04
0.02
0.68
?9?/?1?/?2001
0.03
0.02
0.79
?10?/?1?/?2001
0.02
0.02
0.91
?11?/?1?/?2001
0.02
0.02
0.89
?12?/?1?/?2001
0.02
0.02
0.92
?1?/?1?/?2002
0.02
0.02
0.94
?2?/?1?/?2002
0.02
0.02
0.85
?3?/?1?/?2002
0.02
0.02
0.90
?4?/?1?/?2002
0.02
0.02
0.98
?5?/?1?/?2002
0.02
0.02
1.01
?6?/?1?/?2002
0.02
0.02
0.96
?7?/?1?/?2002
0.02
0.02
0.93
?8?/?1?/?2002
0.02
0.02
0.95
?9?/?1?/?2002
0.02
0.02
1.03
?10?/?1?/?2002
0.02
0.02
1.12
?11?/?1?/?2002
0.01
0.02
1.29
?12?/?1?/?2002
0.01
0.02
1.23
?1?/?1?/?2003
0.01
0.02
1.17
?2?/?1?/?2003
0.01
0.02
1.20
?3?/?1?/?2003
0.01
0.02
1.18
?4?/?1?/?2003
0.01
0.02
1.28
?5?/?1?/?2003
0.01
0.02
1.30
?6?/?1?/?2003
0.01
0.01
1.19
?7?/?1?/?2003
0.01
0.01
1.01
?8?/?1?/?2003
0.01
0.01
1.05
?9?/?1?/?2003
0.01
0.01
1.08
?10?/?1?/?2003
0.01
0.01
1.11
?11?/?1?/?2003
0.01
0.01
1.14
?12?/?1?/?2003
0.01
0.01
1.14
?1?/?1?/?2004
0.01
0.01
1.06
?2?/?1?/?2004
0.01
0.01
1.07
?3?/?1?/?2004
0.01
0.01
1.10
?4?/?1?/?2004
0.01
0.01
1.15
?5?/?1?/?2004
0.01
0.01
1.11
?6?/?1?/?2004
0.01
0.01
1.02
?7?/?1?/?2004
0.01
0.01
0.89
?8?/?1?/?2004
0.02
0.01
0.86
?9?/?1?/?2004
0.02
0.01
0.83
0.85
?9?/?30?/?2005
0.03
0.85
0.03