Answer:
about 68% of brand x’s batteries have a lifespan between 95.2 hours and 108.8 hours. about 68% of brand y’s batteries have a lifespan between 98.6 hours and 101.4 hours. the life span of brand y’s battery is more likely to be consistently close to the mean.
Explanation:
According to the empirical rule (68–95–99.7 rule) for a normal distribution, 68% of the data falls within the first standard deviation (μ ± σ).
Given for brand x, mean (μ) = 102 hours and standard deviation (σ) = 6.8 hours.
first standard deviation (μ ± σ) = 102 ± 6.8 = (95.2, 108.8)
about 68% of brand x’s batteries have a lifespan between 95.2 hours and 108.8 hours.
Given for brand y, mean (μ) = 100 hours and standard deviation (σ) = 1.4 hours.
first standard deviation (μ ± σ) = 100 ± 1.4 = (98.6, 101.4)
about 68% of brand x’s batteries have a lifespan between 98.6 hours and 101.4 hours.
Since the standard deviation of brand y is smaller than that of brand x, brand y battery is more likely to be consistently close to the mean
