The method of tree ring dating gave the following years A. D. for an archaeological excavation site. Assume that the population of x values has an approximately normal distribution. 1313 1243 1271 1313 1268 1316 1275 1317 1275 (a) Use a calculator with mean and standard deviation keys to find the sample mean year x and sample standard deviation s. (Round your answers to the nearest whole number.) x

And replacing we got:

In order to find the sample deviation we can use this formula:

s= \sqrt{\frac{(1313-1287.89)^2 +(1243-1287.89)^2 +(1271-1287.89)^2 +(1313-1287.89)^2 +(1268-1287.89)^2 + (1316-1287.89)^2 +(1275-1287.89)^2 +(1317-1287.89)^2 +(1275-1287.89)^2}{9-1}}= 27.218 \approx 27

Step-by-step explanation:

For this case we have the following data given:

1313 1243 1271 1313 1268 1316 1275 1317 1275

In order to calculate the sample mean we can use the following formula:

And replacing we got:

In order to find the sample deviation we can use this formula:

And replacing we have:

s= \sqrt{\frac{(1313-1287.89)^2 +(1243-1287.89)^2 +(1271-1287.89)^2 +(1313-1287.89)^2 +(1268-1287.89)^2 + (1316-1287.89)^2 +(1275-1287.89)^2 +(1317-1287.89)^2 +(1275-1287.89)^2}{9-1}}= 27.218 \approx 27

a reflection across the x-axis , followed by the by a reflection across the y-axis , and then a scale dilation of 0.5 .