Use benchmarks to estimate the sum, difference, or product. (i need this answered super fast its worth 30 points) question 1-- 1 7/8 + 1/9 question 2-- 7 1/7 - 1 9/10 question 3-- 7 1/13 x 4 15/17

An automobile assembly line operation has a scheduled mean completion time, μ, of 12 minutes. the standard deviation of completion times is 1.6 minutes. it is claimed that, under new management, the mean completion time has decreased. to test this claim, a random sample of 33 completion times under new management was taken. the sample had a mean of 11.2 minutes. assume that the population is normally distributed. can we support, at the 0.05 level of significance, the claim that the mean completion time has decreased under new management? assume that the standard deviation of completion times has not changed.

Jahdzia wears her winter coat when the temperature is colder than -4 degrees celsius. write an inequality that is true only for temperatures (t) at which jahdzia wears her winter coat.

Thirteen bowlers were asked what their score was on their last game. the scores are shown below 190,150,154,194,181,190,170,151,170 ,178,161,180 find the range of the bowlers score a.56 b.44 c.34 d.23