For a certain company, the monthly percentages of all shipments recelved on time over the past 12 months are 80 , 82,84,83,82,84,85, 85 , 82 , 83 , 85 , and 83 , (a) Construct a time series plot. What type of pattern exists in the data? The time series plot shows a linear trend. The time series plot shows a seasonal pattern. The time series plot shows a horizontal pattern. The time series plot shows a nonlinear trend. (b) Use simple linear regression analysis to find the parameters for the line that minimizes MSE for this time series: (Round your numerical values to two decimal places. t= (c) What is the forecast for t=8 ? (Round your answer to one decimal place.)