Statistics in Business Essay Example | Topics and Well Written Essays - 500 words

Statistics in Business - Essay Example When drawing inferences about a population, basically estimation and hypothesis testing is involved. Data may be quantitative or qualitative in nature. Qualitative data is data that is not numerical. Quantitative data on the other hand is numerical (involves numbers). Data can be measured in four levels: nominal, ordinal, interval and ratio (Anderson, Sweeney & Williams, 1994). The lowest of the four levels of data measurement is nominal and deals with labels, categories or names. Data that falls under the nominal level is usually qualitative. At this level, the data cannot be ordered and statistics can not be reasonably drawn from it. The second level of data measurement is ordinal. At this level, the data can only be ordered and ranked with no room to make meaning of the differences between the data. Data that can be ordered and in which sense can be made of their differences can be measured at the interval level. However, the data that falls in this category is known to have no starting point, examples being the Celsius and Fahrenheit scales used to measure temperature (Thompson, 2006). The highest level of data measurement is the ratio level. Data that falls in this category possesses all the characteristics of the interval level. In addition to these, the data has a zero value. Statistics plays an integral role in business decision making in the modern setup. In order to make sound business decisions, for example, an entrepreneur should have a good idea about the demand for their products. Based on statistics, the quality of products produced by a business may be verified (Anderson, Sweeney & Williams, 1994). Furthermore, statistical data may be used by managers to establish or evaluate customer satisfaction, evaluate risks, calculate loss or profit, and calculate financial ratios among other applications, all

Heat transfer in a water-water heat exchanger Lab Report

Heat transfer in a water-water heat exchanger - Lab Report Example The heater and main switch was turned on and the water temperature controller was set at 60oc.The hot water flow rate and cold water flow rate were set to 50g/sec and 15g/sec respectively. The flow rates and stream temperature were monitored making sure that there was temperature stabilization and there was no drift of flow rate. The temperatures were then recorded in the table with the following headings; Repeat with cold water flows of;25g/sec,40g/sec and set the hot water temperature to 40oc and repeat step 2 and 3 The cold water supply was interchanged and the horse connection was returned. At this point, the exchanger had been configured with co-current flow. There was a single set readings made with hot water at 60oc, Vhot=50g/sec and Vcold=40g/sec. The results were recorded in the table The energy gained by cold stream Qc and energy lost from the hot stream was calculated for each run with the use of equations 1 and 2 in the theory sections. It was noted that the indicated flow values V, was to be multiplied by 0.001 to give mass flows (F) in S.I unit of Kg s-1 Basing on the results, it was observed that when the flow rate of the cold water was increased in the first 3, the T6 that is the midpoint also increased. The reading for T1 was never the same as the initial temperature. It is evident that heat transfer rate could be calculated with the use of heat transfer coefficient log mean temperature difference and total area (Shah and Joshi 1987; Gnielinski 1976). The same kind of results is seen to hold for counter flow and parallel heat exchangers whereby there is change in temperature for both fluids. It is not easy to analyze the cross-flow heat exchangers and there is a good estimation to the actual condition when the log mean temperature difference is used in case one stream never changes to a large extent in terms of temperature (Techo, Tickner and James 1965; Moffat 1988). It is not easy to solve heat exchanger problems in