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### Course: AP®︎/College Statistics>Unit 11

Lesson 4: Confidence intervals for the difference of two means

# Two-sample t interval for the difference of means (calculator-active)

## Problem

Fast food companies want their products to be as similar as possible across locations. Miguel is tasked with making sure that two locations of a fast food chain have burger patties of the same size. He takes a random sample of $30$ patties from each location. Here are summary statistics for his samples:
Mass of burger patties
Location ALocation B
Sample mean
Sample standard deviation
Sample size${n}_{\text{A}}=30$${n}_{\text{B}}=30$
Assume that the conditions for inference have been met.
Which of the following is a $90\mathrm{%}$ confidence interval for the difference in mean weight (in grams) of the patties from the two restaurants $\left({\mu }_{\text{A}}-{\mu }_{\text{B}}\right)$?
Use a calculator with statistical capabilities to calculate the interval.