# Confidence interval for mean conductivity & Stemplot

How well a material conducts heat matters when designating houses, for example. Conductivity is measured in terms of watts of heat power transmitted per square meter of surface per degree Celsius of temperature difference on the two sides of the material. In these units, glass has conductivity of about 1. The National Institute of Standards and Technology (NIST) provides data on properties of materials. Here are 11 NIST measurements of the heat conductivity of a particular type of glass:

1.11 1.07 1.11 1.07 1.12 1.08 1.08 1.18 1.18 1.18 1.12

(a) We can consider this an SRS (simple random sample) of all specimens of glass of this type. Make a stemplot. Are there any signs of major deviation from Normality?

(b) Give a 95% confidence interval for the mean conductivity.

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A normal distribution is perfectly symmetric; that is, the skewness is 0. The ...

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This solution provides a step-by-step calculation of 95% confidence interval for mean conductivity. Also included is a stemplot of the variable with comments on its normality.