To evaluate battery life between two types of wireless headphones, a technician tests 2020 units of Brand A and 2525 units of Brand B.Brand A has a mean battery life of 18.218.2 hours\text{hours} with a known population standard deviation of 1.51.5 hours\text{hours}.Brand B has a mean battery life of 17.517.5 hours\text{hours} with a known population standard deviation of 1.81.8 hours\text{hours}.At the α=0.05α = 0.05 level of significance, can the technician conclude that there is a significant difference in the average battery life between the two brands?

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1. Intro to Stats and Collecting Data(0)

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Levels of Measurement
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Sampling Methods
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2. Describing Data with Tables and Graphs(0)

Visualizing Qualitative vs. Quantitative Data
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Frequency Distributions
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Histograms
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Bar Graphs and Pareto Charts
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Pie Charts
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Frequency Polygons
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Time-Series Graph
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3. Describing Data Numerically(0)

Mean
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Median
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Mode
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Standard Deviation
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Interpreting Standard Deviation
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Percentiles & Quartiles
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Boxplots
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Basic Concepts of Probability
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Addition Rule
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Multiplication Rule: Dependent Events
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Discrete Random Variables
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Poisson Distribution
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Hypergeometric Distribution
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Uniform Distribution
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Non-Standard Normal Distribution
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Sampling Distribution of the Sample Mean and Central Limit Theorem
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Introduction to Confidence Intervals
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Confidence Intervals for Population Mean
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Determining the Minimum Sample Size Required
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Sampling Distribution of Sample Proportion
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Chi Square Distribution
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Confidence Intervals for Population Variance
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Steps in Hypothesis Testing
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Performing Hypothesis Tests: Means
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Performing Hypothesis Tests: Variance
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Two Proportions
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Two Means - Unknown, Unequal Variance
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Two Means - Unknown, Equal Variance
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Two Means - Known Variance
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Two-Way ANOVA
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10. Hypothesis Testing for Two Samples

Two Means - Known Variance

10. Hypothesis Testing for Two Samples

Two Means - Known Variance: Videos & Practice Problems

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Problem 5Multiple Choice

To evaluate battery life between two types of wireless headphones, a technician tests $20$ units of Brand A and $25$ units of Brand B.
Brand A has a mean battery life of $18.2$ $hours$ with a known population standard deviation of $1.5$ $hours$ .
Brand B has a mean battery life of $17.5$ $hours$ with a known population standard deviation of $1.8$ $hours$ .
At the $alpha equals 0.05$ level of significance, can the technician conclude that there is a significant difference in the average battery life between the two brands?

There is sufficient evidence to conclude that brand A has significantly higher battery life than brand B.

There is sufficient evidence to conclude that brand B has significantly higher battery life than brand A.

There is insufficient evidence to conclude that the average battery life differs between brand A and brand B.

Insufficient data.

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