Having some trouble on these. Help :( I'm not very good at Stats

Does second-hand smoke increase the risk ofa low birthweight? A baby is considered have low birthweight if he/she weighs less than 5.5 pounds at birth. According to the National Center of Health Statistics, about 7.8% of all babies born in the U5. are categorized as low birthweight. Suspecting that the national percentage is higher than 7.8%, researchers randomly select 1200 babies whose mothers had extensive exposure to second-hand smoke during pregnancy and nd that 10.4% of the sampled babies are categorized as low birth weight. Let p be the proportion of all babies in the US. that are categorized as "low birth weight." Give the null and alternative hypotheses for this research question. 5 Ho:p=0.078 Ha:p:0.078 A Ho:p=0.078 Ha:p>0.078 f\" Ho:p=0.104 Hazp0.104 A H01u=.078 Halu>.078 A quality control engineer at a potato chip company tests the bag lling machine by weighing bags of potato chips. Not every bag contains exactly the same weight. But if more than 15% of bags are over-filled then they stop production to x the machine. They define over-lled to be more than 1 ounce above the weight on the package. The engineer weighs 100 bags and nds that 21 of them are over-filled. He plans to test the hypotheses: Ho: p = 0.15 versus Ha: p > 0.15 (where p is the true proportion of overfilled bags). What is the test statistic? Z=1.68 Z=-1.68 KT Z=4 A Z=-1.47 According to a Pew Research Center, in May 2011, 35% of all American adults had a smart phone (one which the user can use to read email and surfthe Internet). A communications professor at a university believes this percentage is higher among community college students. She selects 300 community college students at random and nds that 120 of them have a smart phone. In testing the hypotheses: Ho: p = 0.35 versus Ha: p > 0.35, she calculates the test statistic as Z = 1.82. Use the Normal Table to help answer the p-value part ofthis question. Click here to access the normal table. A There is enough evidence to show that more than 35% of community college students own a smart phone (P-value = 0.034). A There is enough evidence to show that more than 35% of community college students own a smart phone (P-value = 0.068). b, There is not enough evidence to show that more than 35% of community college students own a smart phone (P-value = 0.966). (7 There is not enough evidence to show that more than 35% of community college students own a smart phone (P-value = 0.034)