John sells t-shirts. Plain shirts cost $5 and graphic shirts cost $7. In order to match his product costs, he must make at least $1,200.
a) Write an inequality to represent this situation.
b) If he sells 150 plain shirts and 60 graphic shirts, will he be able to cover
the product costs?
c) If he sells 90 graphic shirts, what's the minimum number of plain shirts he
must sell to break even? PLEASE DONT COMMENT UNLESS YOU CAN HELP I NEED HELP.

Data on oxide thickness of semiconductors are as follows: 426 432 418 418 421 436 418 408 431 435 423 426 411 434 435 432 411 426 407 439 422 426 412 416 consider this data as a sample of the population. (a) calculate a point estimate of the mean oxide thickness for all wafers in the population. (round your answer to 3 decimal places.) (b) calculate a point estimate of the standard deviation of oxide thickness for all wafers in the population. (round your answer to 2 decimal places.) (c) calculate the standard error of the point estimate from part (a). (round your answer to 2 decimal places.) (d) calculate a point estimate of the median oxide thickness for all wafers in the population. (express your answer to 1 decimal places.) (e) calculate a point estimate of the proportion of wafers in the population that have oxide thickness greater than 430 angstrom. (round your answer to 4 decimal places.)