1. Can we assume that the distribution for the sample means is normal for samples of this size? Explain how you know. 2. Find the mean and standard deviation for your sample. 3. Build a 95% confidence interval for the mean year of creation for all of the objects in the Sheldon's collection. Please include the critical value and margin of error rounded to two decimal places. The limits of your confidence interval should be rounded to only one decimal place. Note: The population standard deviation is unknown, so make sure you're using the formula that uses the sample standard deviation. 4. Write a sentence that gives the practical interpretation of the 95% confidence interval. Outliers One method of flagging outliers is to tag any value that is above Q3 by an amount of 1.5 x IQR or below Q1 by an amount of 1.5 x IQR. 5. Find the first quartile Q1 and third quartile Q3 for your data set. Subtract the two to get the interquartile range IQR. 6. Multiply your IQR by 1.5 and subtract that from Q1. Any data value below the answer is an outlier. List those outliers. 7. Multiply your IQR by 1.5 and add it to Q3. Any data value above the answer is an outlier. List those outliers. 8. If you had any outliers, build a 95% confidence interval for the sample without the outliers and compare it to your answer in part 3. Assessment 9. Are you happy with your confidence interval or does it seem too wide? What could have been done differently to decrease the margin of error? Years Years 1 1966 21 1962 2 1934 22 1939 34 1974 23 1964 1972 24 2021 5 1972 25 1982 6 1973 26 1970 7 1997 27 1971 00 8 1977 28 1940 9 1940 29 1959 10 1980 30 1912 11 1964 31 1997 12 1974 32 2019 13 1976 33 1976 14 1986 34 1977 15 1979 35 1991 16 1956 36 1931 17 1977 37 1959 18 1992 38 1974 19 1923 39 1968 20 1999 40 1935