Step 1 :Identify the null and alternative hypotheses for this test. The null hypothesis \(H_{0}\) is that the proportion of correct guesses by the touch therapists is equal to 0.5, which is what we would expect if they were guessing randomly. The alternative hypothesis \(H_{1}\) is that the proportion of correct guesses by the touch therapists is not equal to 0.5.
Step 2 :Given values are: number of trials \(n = 271\), number of successes \(x = 114\), and proportion under the null hypothesis \(p_0 = 0.5\).
Step 3 :Calculate the sample proportion \(p_{hat}\) by dividing the number of successes by the number of trials: \(p_{hat} = \frac{x}{n} = \frac{114}{271} \approx 0.421\).
Step 4 :Calculate the test statistic \(z\) using the formula: \(z = \frac{p_{hat} - p_0}{\sqrt{\frac{p_0(1 - p_0)}{n}}}\). Substituting the given values into the formula gives \(z \approx -2.61\). This value is negative, indicating that the observed proportion of correct guesses by the touch therapists is less than what we would expect if they were guessing randomly.
Step 5 :The final answer is: The null and alternative hypotheses for this test are: \(H_{0}: p=0.5\) and \(H_{1}: p \neq 0.5\). The test statistic for this hypothesis test is \(\boxed{-2.61}\).