Each chart has which three components (choose three)?
forecast of customer demandforecast of customer demand a center line representing the averagea center line representing the average
a. an upper line representing last week’s sample.
b. a lower line representing last week’s sample.
c. an upper line representing the maximum acceptable variation upwards.
d. a lower line representing the maximum acceptable variation downwards.
e. a center line representing the maximum acceptable variation centrally.