In: Statistics and Probability
Examine the given statement, then express the null hypothesis Upper H 0 and the alternative hypothesis Upper H 1 in symbolic form. More than 29% of Internet users pay bills online. Which of the following is the hypothesis test to be conducted? A. Upper H 0: pequals0.29 Upper H 1: pnot equals0.29 B. Upper H 0: pnot equals0.29 Upper H 1: pequals0.29 C. Upper H 0: pequals0.29 Upper H 1: pgreater than0.29 D. Upper H 0: pless than0.29 Upper H 1: pequals0.29 E. Upper H 0: pgreater than0.29 Upper H 1: pequals0.29 F. Upper H 0: pequals0.29 Upper H 1: pless than0.29
First let us know what is a NULL and ALTERNATIVE HYPOTHESIS.
Null Hypothesis
In the formulation of testing problem the roles of H1 and H2 are not symmetric.In order to decide which of these two hypothesis should be taken as null hypothesis H0 the difference between the roles and the implication of these two terms should be clearly understood. In testing hypothesis a statistician should be completely impartial and should have no brief for any party or company nor should he/she allow his personal views to influence the decision.
The neutral or non-committal attitude of the statistician before the sample values are taken is key to the choice of NULL HYPOTHESIS.
Keeping in mind the potential losses due to the wrong decision, the decision maker is somewhat conservative in holding the null hypothesis as true unless there is a strong evidence that is false to him the consequences of wrongly rejecting a null hypothesis seems to be more serious than those of wrongly accepting it.
Hence we denote by H0 that hypothesis the false rejection of which is regarded as more serious and call it the null hypothesis.
Alternative Hypothesis
It is desirable to state what is called an alternative hypothesis in respect of every statistical hypothesis being tested because the acceptance or rejection of null hypothesis is meaningful only when it is being tested against a rival hypothesis which should rather be explicitly mentioned. Alternative hypothesis is denoted by HA
Example: Let us suppose that two different company manufacture sleeping drugs for inducing sleep. Drug A is manufactured by first company and drug B is manufactured by second company. Each company claims that its drug is better to that of the other and it is desired to test which is superior drug A or drug B? We formulate the statistical hypothesis to see which drug is better. Let X be a random variable which denotes the additional hours of sleep gained by the individual when drug A is given and let the random variable Y denote the additional hours of sleep gained when drug B is used. Hence our null hypothesis and alternative hypothesis is given by,
H0: There is no difference between the effects of two drugs
HA: There is difference between the effects of two drugs i.e. (drug A has more effect than drug B or drug B has more effect than drug A)
Coming back to our problem,
We need to test the claim that whether more than 29% of internet users pay bills online.
Therefore probability 'p' that an internet user pays bills online is 0.29.
So our null hypothesis is that p is equal to 0.29 since "The neutral or non-committal attitude of the statistician before the sample values are taken is key to the choice of NULL HYPOTHESIS"
H0:p=0.29
Now lets come to our alternative hypothesis.
Our claim is that whether more than 29% of internet users pay bills online i.e. p is greater than 0.29
H1:p>0.29
Therefore our Hypothesis are,
H0:p=0.29 against H1:p>0.29
Therefore correct option is C:Upper H0: p equals 0.29 Upper H1: p greater than 0.29