Chapter 14, Problem 6P

12 ம் Y si to no 1672 1 A medical researcher measures bone density and the age of 125 women; you can see the o lesummary of statistics in the following table. (See the figure in Question 2 for a scatterplot of this data.) a. How well will a line fit this data? b. Find the equation of the best fitting regression line. Variable Mean Standard Correlation Deviation Bone loss (Y) 35.008 7.684 0.574 A Age (X) 19 67.992 10.673 T in send art lo (d) sqala sala bolt 3 esmit sqola ad g

In a study of 70 undergraduate students and 47 graduate students, the undergraduates had a mean reported number of hours sleeping of 6.0998 with a standard deviation of 1.1085 hrs. The graduate students had a mean of 6.6255 hours with a standard deviation of 1.8992 hours. Use StatCrunch and a significance level of 0.05 to run the t-test. What is the test statistic? What is the p-value associated with that test statistic? Give the most appropriate conclusion in context There is not evidence to reject the claim that undergraduates sleep the less than graduate students. There is evidence to support the claim that undergraduates sleep less than graduate students. We accept the claim that undergraduates sleep less than graduate students. Undergraudates sleep the same amount of time as graduate students.

1 14 Agricultural scientists try to predict corn sed production by using annual rainfall. They measure crop yields (bushels per acre) and besnil annual rainfall (inches) for 150 one-acre Xlo plots; you can see the summary of statistics to sgn in the following table. sulay X a. lg noy nativ Identify the X variable and the Y variable in this problem. b. Find and try to interpret the slope in the en adi gnis context of corn and rainfall. (More prac- qo X to tice on interpretation in the next section.) 6 Variable Mean Standard Correlation Deviation remis Rainfall 47.844 47.844 9.38 9.38 0.608 Corn 150.77 19.76 itsch mot sugiterü gizl e di mot) moldong signers dziw Y bas Xgnitis"

14 Agricultural scientists try to predict corn dm production by using annual rainfall. They sb measure crop yields (bushels per acre) and annual rainfall (inches) for 150 one-acre plots; you can see the summary of statistics ag in the following table. solv a. Identify the X variable and the Y variable in this problem. b. Find and try to interpret the slope in the or gris context of corn and rainfall. (More prac- 03 X to tice on interpretation in the next section.) gob 11.Y to smontuo ed i sad s 6 Variable Mean Standard Deviation Correlation niroq Rainfall 47.844 do no 47.844 9.38 0.608 10 Corn 150.77 19.76 to s fods about sugi orgie

13 A wol number of putts hit for 100 rounds of golf an amateur plays; you can see the summary of guig statistics in the following table. (See the anteu figure in Question 3 for a scatterplot of this nobis data.) moitoloqorxs bel nedW Diplogos bello al silos a. Is it reasonable to use a line to fit this data? Explain. b. Find the equation of the best fitting pl97 1590 regression line. zazumɔ X ni ogrados em noob Y to sul Variablem Mean Standard Correlation E Deviation 870 Total score (Y) 93.900 7.717 0.896 1211 Putts hit (X) 35.780 4.554 tot anolinibong solam riss uoy X to asulsy doldw grib onil edi 08,080.0 xl notion ofT.A od? How ath

bropupme 7 Using the toddler data table in Question 1, describe the toddlers in the sample with joint101 probabilities only. It TOTAL: 4+24+2+12=42 (mn LH) 4/42 = 2/21=0.0952 adrat aoismet to nothogong ad d zon xe jooge fox (D) rots (300): 60 erit 15:

12 A medical researcher measures bone density and the age of 125 women; you can see the d of summary of statistics in the following table. (See the figure in Question 2 for a scatterplot of this data.) D 30 a. How well will a line fit this data? b. Find the equation of the best fitting regression line. Variable Mean Standard Correlation Y Deviation Bone loss (Y) 35.008 7.684 0.574 Age (X) 1967.992 10.673 Las

5 Calculate the correlation of the data set (3,2), (3, 3), (6, 4). 1 tot si riteri sta2 alsɗand new "asrond & ai listuisi isonas bois 906 190

betonab) 11 A coffee barista records the temperature (degrees Fahrenheit) and number of coffees noirs sold for 50 professional football games; you can see the summary of the statistics in the following table. (See the figure fromb Question 1 for a scatterplot of this data.) a. Should you use a line to fit this data? Justify your answer. b. Find the equation of the best fitting regression line. Variable Mean Standard Correlation Deviation Temperature (X) 35.08 16.29 -0.741 Coffees sold (S) 29,913 12,174 ma "vi gld" siglo del grind