2. ABC Company sells kiwi fruits. Suppose the weight of a kiwi fruit is normally distributed with mean \( 21\mathrm{g} \) and standard deviation of \( 2\mathrm{g} \). There are 16 kiwi fruits packed in a box. The probability that a box of kiwi fruits weights less than \( 340\mathrm{g} \) is       3.      (5%)
Mary buys 5 boxes of kiwi fruits. The probability that there is only one box of kiwi fruits weights less than 340 g is       4.      .(5%)
ABC Company claims that the average weight of a kiwi fruit is at least 21 g. Mary buys 5 boxes of kiwi fruits and find the average weight of 20.5 g for a kiwi fruit. Is the test for this hypotheses significant at $\alpha=0.05$?       5.      .(5%)