previously, 2% of mothers smoked more than 21 cigarettes during their pregnancy. an obstetrician believes that the percentage of mothers who smoke 21 cigarettes or more is less than 2% today. she randomly selects 160 pregnant mothers and finds that 2 of them smoked 21 or more cigarettes during pregnancy.

step-by-step explanation:

ok so im not 100% sure but you would start by adding 5.1t and 1.9t beacuse they have the same variable. that is 7t.   then add -3.6 + 1.2 which is -2.4

so then keep that as -2.4 + 7t. i apologize if this is incorrect. best luck on your test < 3

1^3 + 2^3 + 3^3 +4^3 = (1+2+3+4)^2

step-by-step explanation:

i am only able to answer the first part. i am not sure about the second part. sorry