Bell Greenhouses has estimated its monthly demand for potting soil to be the following: N=400+8X where N is the monthly demand for bags of potting soil and X is the time period in months (March 2016 = 0). Assume this trend factor is expected to remain stable in the foreseeable future. The following table contains the monthly seasonal adjustment factors, which have been estimated using actual sales data from the past five years: Complete the following table by forecasting Bell Greenhouses' demand for potting soil in March, June, August, and December 2017. Month March Adjustment Factor (%) Forecast June August December +2 +15 +10 -12 The following table shows the forecasted and actual potting soil sales by Bell Greenhouses for April in five different years. Year Forecast Actual 2017 504 549 2016 408 412 2015 312 340 2014 216 227 2013 120 131 What seasonal adjustment factor would you recommend be used to forecast in April 2018? оо -1.5% ○ 2.9% ○ 6.6%