Im giving brainlyest to first CORECT answer and 30points QUICKKKKKK

Find a 90% confidence interval for the mean of all tree ring dates from this archaeological site. (round your answers to the nea

creativ13 [48]

Given a table below which gives the years in A.D. for an archaeological excavation site using the method of tree ring dating:

$\begin{tabular}
{|c|c|c|c|c|c|c|c|c|}
1229&1292&1187&1257&1268&1316&1275& 1317&1275
\end{tabular}$

Part A:

The sample mean is given by:

$\bar{x}= \frac{1229+1292+1187+1257+1268+1316+1275+ 1317+1275}{9} \\ \\ = \frac{11416}{9} =1268$

Therefore, the sample mean is 1268.

Part B:

We calculate the sample standard deviation as follows:

$s= \frac{1}{9-1} \left(\sqrt{(1229-1268)^2+(1292-1268)^2+(1187-1268)^2+(1257-1268)^2+(1268-1268)^2+(1316-1268)^2+(1275-1268)^2+(1317-1268)^2+(1275-1268)^2}\right)\\ \\ = \frac{1}{8}\left(\sqrt{(-39)^2+24^2+(-81)^2+(-11)^2+0^2+48^2+7^2+49^2+7^2}\right)\\ \\ = \frac{1}{8}\left(\sqrt{1521+576+6561+121+2304+49+2401+49}\right)\\ \\ = \frac{1}{8}\left(\sqrt{13,582}\right)\\ \\ = \frac{1}{8}(116.54)=14.57\approx15$

Part C:

The 90% confidence interval is given by:

$90\% \ C. \ I.=1268\pm1.65\left(\frac{15}{\sqrt{9}}\right) \\ \\ =1268\pm\left(\frac{15}{3}\right)=1268\pm5 \\ \\ =(1268-5, \ 1268+5)=(1263, \ 1273)$

8 0

3 years ago

Select the expression that shows the value of one of the digits in the number below.

Snowcat [4.5K]

Answer:

04×100,06×10,01×1

set this equation

7 0

3 years ago

Which is the simplified form of the expression 3(7/5x+4) - 2(3/2 - 5/4x)?

Kruka [31]

Answer:

B. $\frac{67}{10} x + 9$

Step-by-step explanation:

Simplify the expression. Remember to go by the order of operations, or PEMDAS.

1) First, distribute the numbers outside of the set of parentheses to the terms inside the set of parentheses next to them. Then, simplify the fractions.

$3(\frac{7}{5} x + 4) -2 (\frac{3}{2} -\frac{5}{4} x)$

$\frac{21}{5}x + 12 - \frac{6}{2} + \frac{10}{4} x$

$\frac{21}{5} x + 12 - 3 + \frac{10}{4} x$

2) Finally, combine like terms. (This means to add or subtract constants and to add or subtract terms with the same variables.) You may need to convert terms to the same denominator in order to do so easier. Then, reduce the fraction.

$\frac{21}{5} x + 9 + \frac{10}{4}x \\\frac{84}{20}x + \frac{50}{20}x + 9 \\\frac{134}{20}x + 9 \\\frac{67}{10}x + 9$