Hi, could you help me on this question?

A health survey of females living in the UK asked individuals, not registered with a private dentist, whether they had been to a dentist in the last year. For a random sample of 196, 49 reported not having seen a dentist. (a) At the 5% signicance level test the hypothesis that the attendance at a dentist for females, who are not registered with a private practice, is the same as that which was observed 10 years ago which was 30% against a l-sided alternative that it is less. (b) Assuming the sample statistics remain unchanged, what sample size would have been needed to ensure you found a significant test statistic for the test in (a). (c) Calculate the critical value for the distribution of the sample mean under the null hypothesis corresponding to the test in (a). (d) Assuming the true proportion not having seen a dentist is 25%, on a diagram plot the signicance level and power of the test in (a)