# Pex Exercise 2 Activity 6

**Topics:**Statistics, Statistical significance, Statistical hypothesis testing

**Pages:**3 (400 words)

**Published:**February 4, 2013

Introduction to non-Calculus based Statistics Home work 7

Name:

Section: _______

Complete your answers logically in the spaces provided. Give final answers/conclusions in complete sentences in context of the question. 1. Carry out complete 5 steps of hypothesis testing using traditional method and alongside that, show p-value estimates that confirm your conclusions on any ttests that are carried out for this question. Below is data on number of tree species in 12 unlogged forest plots and 9 similar plots logged 8 years ago. Unlogged Logged 22 17 18 4 22 18 20 14 15 18 21 15 13 15 13 10 19 12 13 19 15

a. Test at the 5% significant level that mean number of species in logged plots is significantly lower than the mean number of species in unlogged plots after 8 years. (5 marks)

Home work 7

1

MATH1050 Y –B FW2012

Introduction to non-Calculus based Statistics

b. Identify the outlier. If it is removed, does your conclusion change for the 5% significant level test in a. (carry out the final test again assuming no change in your conclusion about your test on variances in part a.) (5 marks)

2. Exercises 8-3; Question number 14 of the text (Triola). The Alberta government records freezing dates for over a hundred locations around the province. Based on average last frost dates for spring, a researcher has proposed dividing the province into early last-frost locations and late last-frost locations. Refer to Data set 17 of the text book in Appendix B. (in the CD). Use the day of year columns to test, at the 0.01 significance level, the claim that the late last frost locations have a different mean date for last spring frost than the early last-frost locations.(Use calculators to find the mean, standard deviation and variances etc)

Home work 7

2

MATH1050 Y –B FW2012

Introduction to non-Calculus based Statistics

a. Conduct the hypothesis test using the traditional method. (5 marks)

b. Conduct the...

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