management 2019s discussion and analysis of financial condition and results of operations 2013 ( continued ) ( amounts in millions , except per share amounts ) liquidity and capital resources cash flow overview the following tables summarize key financial data relating to our liquidity , capital resources and uses of capital. .
what is the mathematical range for net cash provided by ( used in ) financing activities?
1 reflects net income adjusted primarily for depreciation and amortization of fixed assets and intangible assets , amortization of restricted stock and other non-cash compensation , net losses on sales of businesses and deferred income taxes . 2 reflects changes in accounts receivable , accounts receivable billable to clients , other current assets , accounts payable and accrued liabilities . operating activities due to the seasonality of our business , we typically use cash from working capital in the first nine months of a year , with the largest impact in the first quarter , and generate cash from working capital in the fourth quarter , driven by the seasonally strong media spending by our clients . quarterly and annual working capital results are impacted by the fluctuating annual media spending budgets of our clients as well as their changing media spending patterns throughout each year across various countries . the timing of media buying on behalf of our clients across various countries affects our working capital and operating cash flow and can be volatile . in most of our businesses , our agencies enter into commitments to pay production and media costs on behalf of clients . to the extent possible , we pay production and media charges after we have received funds from our clients . the amounts involved , which substantially exceed our revenues , primarily affect the level of accounts receivable , accounts payable , accrued liabilities and contract liabilities . our assets include both cash received and accounts receivable from clients for these pass-through arrangements , while our liabilities include amounts owed on behalf of clients to media and production suppliers . our accrued liabilities are also affected by the timing of certain other payments . for example , while annual cash incentive awards are accrued throughout the year , they are generally paid during the first quarter of the subsequent year . net cash provided by operating activities during 2018 was $ 565.1 , which was a decrease of $ 316.7 as compared to 2017 , primarily as a result of an increase in working capital usage of $ 436.4 . working capital in 2018 was impacted by the spending levels of our clients as compared to 2017 . the working capital usage in both periods was primarily attributable to our media businesses . net cash provided by operating activities during 2017 was $ 881.8 , which was an increase of $ 369.0 as compared to 2016 , primarily as a result of an improvement in working capital usage of $ 415.6 . working capital in 2017 benefited from the spending patterns of our clients compared to 2016 . investing activities net cash used in investing activities during 2018 consisted of payments for acquisitions of $ 2309.8 , related mostly to the acxiom acquisition , and payments for capital expenditures of $ 177.1 , related mostly to leasehold improvements and computer hardware and software. .