Answer: The increase in the percent of household with cable television = 45.5%.
Explanation:
Given : The percentage of households in the u.S. With cable television increased from 22.5% in 1980 to 68% in 2000.
i.e. Previous percentage in 1980 = 22.5%
New percentage in 2000= 68%
Now , the increase in percentage = (New percentage) - ( Previous percentage )
= 68% - 22.5%
= 45.5%
Hence, the increase in the percent of household with cable television = 45.5%.