In hypothesis testing one wishes to show real effects of an experiment. By showing that the experimental results were unlikely, given that there were no effects, one may decide that the effects are, in fact, real. The
hypothesis that there were no effects is called the NULL HYPOTHESIS. The symbol H0 is used to abbreviate the Null Hypothesis in statistics. Note that,
unlike geometry, we cannot prove the effects are real, rather we may decide the effects are real.
Probability is a theory of uncertainty. Probability theory is a rational means of dealing with an uncertain world. Probabilities are numbers associated with
events that range from zero to one (0-1). A probability of zero means that the event is impossible. For example, if I were to flip a coin, the probability of a leg
is zero, because a coin may have a head or tail, but not a leg. Given a probability of one, however, the event is certain. For example, if I flip a coin the
probability of heads, tails, or an edge is one, because the coin must take one of these possibilities.
sed on weakened health of companies in many countries. They also studied cheating and manipulating cases in financial reports and observed corporate governance of sampled entities. Those reports have confirmed the following: A. The need of having internal auditing function in all companies. B. The internal auditing management has to perform an effective role in governing and evaluating control systems and managing risks. This role of modern auditing is vague and does not define the functions and responsibilities of the internal auditor clearly towards risk management, observation and governing; so it motivates the researcher to study and reveal the role of internal auditing in Libyan industrial companies. 1.2. Issue of study: In the last few years, the increase of bankruptcy, insolvency cases and failure in many companies lead to more interest in internal auditing systems and to the urgent need to activate what is known as company governance. Concerns regarding the necessity of improving the role of internal auditor and adding new functions to the auditor to help in avoiding bankruptcy, insolvency and financial trespasses, particularly after the failure of external auditor in early detection of business risks and in issuing unmodified reports. Being all the time inside the company enables the internal auditor to become more aware of the nature of operations and the level of performance, and also to follow all the actions and all aspects of related activities. The internal auditor also performs a regular test around the year in order to include all types of company operations. So the functions performed by the internal audit of the company have developed. Namely, internal audit become that kind of function which is no longer limited to just testing financial and accounting operations, or even all company operations, it has got the role of testing and evaluating observation systems, and finding and evaluating risks surrounding the activities of the company which reduces related risks in accomplishing the targets of the company. The internal auditing has become a major component of any governing process in the company; it is the function that connects all governing components in the company (management board, auditing committee, external auditor), these various functions have made the internal auditing an activity that adds value. Most professional reports dealing with these developments have confirmed the role of internal auditing in testing and in evaluating observation systems, and in finding out and evaluating treating these risks and governing them. However, the internal audit function in Libya is still concentrating on exercising its traditional role and carrying out the observational function. Therefore, the importance of this role is significant and it should be revealed to industrial companies in Libya in order to illustrate how internal auditing can contribute in supporting the manage