A large school district claims that 80% of the children are from low-income families. 130 children from the district are chosen to participate in a community project. Of the 130 only 72% are from low-income families. The children were supposed to be randomly selected. Do you think they really were?

d. What is the SD of the null box? (Note: We don't have to estimate the SD of the box from the sample SD because we can compute it directly from the percent of 1's in the null box. This is why we never use a t-test for problems that can be translated into 0-1 boxes.) 0.35 Use the shortcut formula. E 551. Tries 2/3 L'XE: 33 \"iii e. What is the standard error of the % of 1's in the draws? (Round to 2 decimal places.) % E$ i'iana. Tries 1/3 L'AEI 995%? f. What is the value of the test statistic 2? (Round answer to 2 decimal places.) -2.0315 Check the sign of your answer. gazes gig. Tries 1/3 W