Find the solution to the system<br> of equations.

Bonnie volunteers to bring bags of candy to her child’s class for the Halloween party this year. She buys one bag of candy A con

lawyer [7]

Answer:

345 bags and would each have 2

8 0

3 years ago

HELP ASAP!!! DUE IMMEDIATELY!!!

Setler [38]

Answer:

Angle ABD is 16 degrees and Angle DBC is 74 degrees

Step-by-step explanation:

Question 6. x+9+11x-3=90. 12x+6=90 -6 on both sides and 12x=84 divide each side by 12 and x= 7 angle ABD is x+9 so 7 +9= 16. Angle measure of ABD is 16 degrees. Measure of angle DBC is 11x -3 so 11 times 7=77. 77-3= 74. So the measure of angle DBC is 74 degrees and this answer is right because they both add up to be 90 degrees. Hope this helped! :)

7 0

2 years ago

An SRS of 350 high school seniors gained an average of x¯=21 points in their second attempt at the SAT Mathematics exam. Assume

Lynna [10]

Answer:

a) $21-2.58\frac{52}{\sqrt{350}}=13.83$

$21+2.58\frac{52}{\sqrt{350}}=28.17$

So on this case the 99% confidence interval would be given by (13.83;28.17)

b) $ME=2.58\frac{52}{\sqrt{350}}=7.17$

c) $ME=2.58\frac{52}{\sqrt{100}}=13.42$

d) D. Decreasing the sample size increases the margin of error, provided the confidence level and population standard deviation remain the same.

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".

Part a

$\bar X=21$ represent the sample mean

$\mu$ population mean (variable of interest)

$\sigma=52$ represent the population standard deviation

n=350 represent the sample size

99% confidence interval

The confidence interval for the mean is given by the following formula:

$\bar X \pm z_{\alpha/2}\frac{\sigma}{\sqrt{n}}$ (1)

Since the Confidence is 0.99 or 99%, the value of $\alpha=0.01$ and $\alpha/2 =0.005$ , and we can use excel, a calculator or a table to find the critical value. The excel command would be: "=-NORM.INV(0.005,0,1)".And we see that $z_{\alpha/2}=2.58$