Respuesta :
Answer:
84.38, 73.74
Step-by-step explanation:
score given 81.6, 72.0, 81.1, 86.4, 70.2, 83.1
sample size (n) = 6
[tex]mean = \dfrac{81.6+ 72.0+ 81.1+ 86.4+ 70.2+ 83.1}{6}[/tex]
mean = 79.06
standard deviation
[tex]\sigma =\sqrt{\frac{\sum (x-\bar{x})^2}{n-1}}[/tex]
[tex]\sigma =\sqrt{\frac{ (81.6-79.06)^2+(72-79.06)^2+(86.4-79.06)^2+(70.2-79.06)^2+(81.1-79.06)^2+(83.1-79.06)^2}{6-1}}[/tex]
σ = 6.47
level of significance (α) = 1 - 90% = 10%
confidence interval
[tex]\bar{x} \pm t_{\alpha}(\frac{S}{\sqrt{n}})\\79.06 \pm 2.015(\frac{6.47}{\sqrt{6} })[/tex]
=79.06 ± 5.32
= 84.38, 73.74
