∆PQR and ∆SQT are similar, so corresponding sides occur in fixed ratios with one another. This means
SQ / PQ = ST / PR
Solve for x :
8 / ((x + 5) + 8) = (x - 9) / 21
8 / (x + 13) = (x - 9) / 21
168 = (x - 9) (x + 13)
168 = x² + 4x - 117
x² + 4x - 285 = 0
(x + 19) (x - 15) = 0
⇒ x = -19 or x = 15
But x can't be smaller than 9, otherwise ST = x - 9 would be a negative length. So x = 15.
When rounding to the hundredth, you must look at the thousandths place. In this case the thousandths place is less than 5 so it rounds down to 0, making the rounding .17
Answer:
the correct answer is B. $336
Step-by-step explanation:
you first add 319 and 28. Then, you subtract the product with 11.
Answer:
Step-by-step explanation:
Previous concepts
A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population means lies between an upper and lower interval".
The margin of error is the range of values below and above the sample statistic in a confidence interval.
Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".
The population proportion have the following distribution
For this case the standard error is given by:
Solution to the problem
For this case we want to find the probability that the sample proportion will be within +-.03 of the population proportion like this:
And for this case we can use the following z score:
And using this formula we got:
And we can find this probability like this:
Your answer will be 3x^2-7x.