a pile of blocks has 40 blocks in the bottom row 36 blocks in the second row 32 blocks in the third row and so on until there are only 4 blocks on the top row how many blocks are there in 7th row? how many blocks are there in all​

Rachel is studying the population of a particular bird species in a national park. she observes every 10th bird of that species that she can find in the park. her conclusion is that the birds living in the park who belong to that species generally feed on insects. rachel's sample is . based on the sample she picked, rachel's generalization is