A statistical program is recommended.

Electric power consumption is measured in kilowatt-hours (kWh). The local utility company offers an interrupt program whereby commercial customers that participate receive favorable rates but must agree to cut back consumption if the utility requests them to do so. A certain company cuts back consumption at 12:00 noon Thursday. To assess the savings, the utility must estimate the company's usage without the interrupt. The period of interrupted service was from noon to 8:00 p.m. Data on electric power consumption for the previous 72 hours are available.

Time Period	Monday	Tuesday	Wednesday	Thursday
124 a.m.		19,281	31,219	27,340
48 a.m.		33,205	37,014	32,715
812 noon		99,516	119,978	152,465
124 p.m.	124,309	123,666	156,033
48 p.m.	113,545	111,727	128,899
812 midnight	41,310	48,122	73,923

(a)

Is there a seasonal effect over the 24-hour period?

Yes, the time series plot indicates a seasonal effect with a possible linear trend.No, the time series plot indicates a horizontal pattern. No, the time series plot indicates a curvilinear trend with no seasonal effect.No, the time series plot indicates a linear trend with no seasonal effect.

(b)

Compute seasonal indexes for the six 4-hour periods. (Round your answers to four decimal places.)

Time Period	Seasonal Index	Adjusted Seasonal Index
124 a.m.
48 a.m.
812 noon
124 p.m.
48 p.m.
812 midnight

(c)

Use trend adjusted for seasonal indexes to estimate the company's normal usage (in kWh) over the period of interrupted service. (Round your answer to the nearest integer.)

kWh