Please help!!!! !!!!!!!!

Mathematics

1 answer:

Darina [25.2K]3 years ago

4 0

Step-by-step explanation:

Sum of all interior angles = 900°

A+B+C+D+E+F+G=900

120+B+148+90+142+130+129=900

B=900-759

B=141°

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The equation 4x + 2 = x + 8 is modeled above. What value of x makes the equation true? Select one:

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Step-by-step explanation:

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3 years ago

A pile of 55 coins, consisting of nickels and dimes, is worth $3.90. find the number of each.

Lady_Fox [76]

Answer is: 32 nickels and 23 dimes.
x - number of nickels .
y -number of dimes.
two equations in two unknowns:
1) x + y = 55
2) 0,05x + 0,1y = 3,90.
nickel is a five-cent coin.
dime is a ten-cent coin.
solve equation 1) for x and substitute for x in equation 2)
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4 years ago

Read 2 more answers

he American Heart Association is about to conduct an anti-smoking campaign and wants to know the fraction of Americans over 45 w

Sonja [21]

Answer:

The 85% confidence interval is (0.2187, 0.2613).

Step-by-step explanation:

We have a large sample of size n = 830 Americans over 45. We have observed that 631 people don't smoke. Let p be the population proportion of Americans over 45 who smoke. An point estimate of p is $\hat{p} = 199/830 = 0.24$ and an estimate of the standard deviation of $\hat{p}$ is $\sqrt{\hat{p}(1-\hat{p})/n} = \sqrt{(0.24)(0.76)/830}$ = 0.0148. Therefore, because we have a large sample, the 85% confidence interval for the population proportion is given by $\hat{p}\pm z_{\alpha/2}\sqrt{\hat{p}(1-\hat{p})/n} = 0.24\pm z_{0.15/2}0.0148 = 0.24\pm z_{0.075}0.0148$ where $z_{0.075}$ is the 7.5th quantile of the standard normal distribution, i.e., -1.4395. Therefore the 85% confidence interval is $0.24\pm (1.4395)(0.0148)$ or equivalently (0.2187, 0.2613).