2. (a) An energy company claims there has been a signicant increase in the percentage of customers taking out fixed price deals. In the past 20% of customers had this policy, but during the last month 45 of 180 new deals were of this type. Test whether the claim of the energy company is correct at the 5% level of significance. (5 marks) (b) A mobile phone company want to test the claim that their batteries last more than 24 hours. Using a random sample of 16 batteries gave a mean of22 hours, with a standard deviation of 3.5 hours. Test this claim at the 1% level of significance