Orange tabbies. Suppose that 90% of orange tabby cats are male. Determine if the following statements are true or false, and explain your reasoning.
(a) The distribution of sample proportions of random samples of size 30 is left skewed.
(b) Using a sample size that is 4 times as large will reduce the standard error of the sample proportion by one-half.
(c) The distribution of sample proportions of random samples of size 140 is approximately normal.
(d) The distribution of sample proportions of random samples of size 280 is approximately normal.