4.2 Measuring Evidence with P-Values We want to have a survey and ask people working for IT companies if they prefer Skype to mobile phones for making calls. We want to show that, in IT companies, more than 20% of employees prefer to use Skype rather than a mobile phone. The null hypothesis is Ho :p = 0.2. State the alternative hypothesis and whether we should use a left-tail, a right-tail or a two-tailed test to support the alternative hypothesis. O The alternative hypothesis is Ha : p # 0.2. We should use a two-tailed test since we are interested in the values not equal to 0.2. The alternative hypothesis is Ha : p 0.2. We should use a left-tail test since we are interested in the values to the left of 0.2. O The alternative hypothesis is Ha : p > 0.2. We should use a right-tail test since we are interested in the values to the right of 0.2