Question

a) Do older children consume more sweetened drinks? Use 0.05 level of significance? 2. A study looked at beverage consumption among children. It compared 20 children who were 7 to 10 years old with 5 who were 11 to 13. The younger children consumed an average of 8.2 oz of sweetened drinks per day, while the older ones averaged 14.5 oz. The standard deviations were 10.7 oz and 7.9 oz respectively. Ha b) report a 95% confidence interval for the difference in means. 1. Mentily inferential procedure Explain 1. Identity inferential procedure. Explain 2. Report the Standard Error. Write the formal 2. Report the Standard Error Report Standardued Test Stati 3. Report pois estimate and margin of error. Write the interval in plus minu and interval forms 4. Report degrees of freedom and crical 4. Report degree of teem 5. Interpret the intera 5. Conduisenthe

Answer 1

WHEN VARIANCES ARE EQUAL 105.4326 10.26804 5.134019 5 PV= 7.9 S.D 20 S.E 10.7 14.5 8.2 DIFFERENCE OF MEANS 23 1.227108795 0.116097328 0.232194657 MEAN 1 MEAN 2 DEGREES OF FREEDOM T TEST STATISTIC P VALUE FOR ONE TAILED P VALUE FOR TWO TAILED 6.3

INFERENTIAL PROBLEM DO OLDER CHILDREN CONSUME MORE SWEETENED DRINKS ?

2] STANDARD ERROR: SP* SQRT(1/N1+1/N2)

WHERE SP IS POOLED STANDARD DEVIATION

POOLED VARIANCE=((n1-1)*s1^2+(n2-1)*s2^2)/(n1+n2-2)

=105.4326

Sp= sqrt(105.4326)=10.2680

STANDARD ERROR OF MEAN=5.134

3] TEST STATISTIC= DIFFERENCE/STANDARD ERROR OF MEAN

= 6.3/5.134

=1.23

4] DEGREES OF FREEDOM= N1+N2-2= 20+5-2= 23

P VALUE=0.1161

5] SINCE P VALUE GREATER THAN THE LEVEL OF SIGNIFICANCE 0.05 THEREFORE NOT SIGNIFICANT .

DECISION: REJECT H0.

WE DO NOT SUFFICIENT EVIDENCE TO CONCLUDE THAT OLDER CHILDREN CONSUME MORE SWEETENED DRINKS.

B] 1)DO OLDER CHILDREN CONSUME MORE SWEETENED DRINKS.

2) STANDARD ERROR= 5.134

3] MARGIN OF ERROR = t critical* standard error= 2.069*5.134= 10.62

4] degrees of freedom= 23

t critical= 2.069

6.3$\pm$10.62= (-4.32 ,16.92)

95% interval (-4.32 ,16.92)

5] You can be 95% confident that the population mean (μ)difference falls between -4.32 and 16.92.