11. A customer purchases a stroller and packs of diapers from a store. The table shows the total cost, in dollars, based on the number of packs of diapers purchased, x.
Packs of Diapers 2
Total Cost (in dollars) $450
6 10
$550 $650
Which function models the relationship between the number of packs of diapers, x, and the
total cost, f(x)?
A f(x) = 25x + 400
B f(x) = 25x + 450
C f(x) = 50x + 400
D f(x) = 50x + 450

Atechnician compares repair costs for two types of microwave ovens (type i and type ii). he believes that the repair cost for type i ovens is greater than the repair cost for type ii ovens. a sample of 6767 type i ovens has a mean repair cost of $79.79$⁢79.79. the population standard deviation for the repair of type i ovens is known to be $19.18$⁢19.18. a sample of 5555 type ii ovens has a mean repair cost of $75.24$⁢75.24. the population standard deviation for the repair of type ii ovens is known to be $21.40$⁢21.40. conduct a hypothesis test of the technician's claim at the 0.050.05 level of significance. let μ1μ1 be the true mean repair cost for type i ovens and μ2μ2 be the true mean repair cost for type ii ovens. step 2 of 4 : compute the value of the test statistic. round your answer to two decimal places.