Problem: An international research claims that the mean age at which children start walking is 13 months. Reanna wanted to check if this claim is true in the Philippines, she took a random sample of 14 children and the number of months is shown in the table using 5 % significance level. Can you conclude that the mean age at which all children start walking is different from $3 _ months? Assume that the age of which all children start walking have an approximately normal distribution. 12 8 14 15 12 10 9 7 13 11 17