In fitting a model to classify prospects as purchasers or non-purchasers, a certain company drew the training data from internal data that include demographic and purchase information. future data to be classified will be lists purchased from other sources, with demographic (but not purchase) data included. it was found that "refund issued" was a useful predictor in the training data. is this an appropriate variable to include in the model?

a. yes

b. no

Anew firm is developing its business plan. it will require $615,000 of assets, and it projects $450,000 of sales and $355,000 of operating costs for the first year. management is reasonably sure of these numbers because of contracts with its customers and suppliers. it can borrow at a rate of 7.5%, but the bank requires it to have a tie of at least 4.0, and if the tie falls below this level the bank will call in the loan and the firm will go bankrupt. what is the maximum debt ratio the firm can use? (hint: find the maximum dollars of interest, then the debt that produces that interest, and then the related debt ratio.)a. 41.94%b. 44.15%c. 46.47%d. 48.92%e. 51.49%