An auto mechanic knows the average time it takes to replace a defective car radiator is 70 minutes with a standard deviation of 12 minutes. this average is based on a random sample of 50. which excel statements will construct a 90% confidence interval for the time needed to replace a defective car radiator? a. =70+1.96*12/sqrt(50), and =70-1.96*12/sqrt(50) b. =70+1.96*3.46/sqrt(50), and =70-1.96*3.46/sqrt(50) c. =70+1.645*3.46/sqrt(50), and =70-1.645*3.46/sqrt(50) d. =70+1.645*12/sqrt(50), and =70-1.645*12/sqrt(50) e. none of the above.

answer: i don't understand it

step-by-step explanation: sorry

c.   x=2.4cm

step-by-step explanation:

similar triangles are triangles which have the same shape but not the same size. this means their angle measures are equal but their side lengths are not instead they are proportional. to solve, we will set up a proportion and solve.

a proportion is two equal ratios set equal to each other. we form the ratios by finding corresponding sides (sides which match to each other on both triangles by their position). out ratios will be one side of the small triangle over the corresponding side on the big triangle as shown below:

.

to solve the proportion, we'll cross multiply by multiplying numerator with denominator across the equal sign.