a manufacturer of cell phones would like to estimate how much longer the battery lasts in their model 10…

a manufacturer of cell phones would like to estimate how much longer the battery lasts in their model 10 phone than in their model 9 phone. to estimate this difference, they randomly select 40 cell phones of each model from the production line. they subject each phone to a standard battery life test. the 40 model 10 phones have a mean battery life of 14.4 hours with a standard deviation of 2.1 hours. the 40 model 9 phones have a mean battery life of 12.8 hours with a standard deviation of 2.3 hours. what is the appropriate inference procedure to be used to estimate how much longer the battery lasts in their model 10 phone than in their model 9 phone?\no t confidence interval for a mean\no z confidence interval for a proportion\no t confidence interval for a difference in means\no z confidence interval for a difference in proportions

a manufacturer of cell phones would like to estimate how much longer the battery lasts in their model 10 phone than in their model 9 phone. to estimate this difference, they randomly select 40 cell phones of each model from the production line. they subject each phone to a standard battery life test. the 40 model 10 phones have a mean battery life of 14.4 hours with a standard deviation of 2.1 hours. the 40 model 9 phones have a mean battery life of 12.8 hours with a standard deviation of 2.3 hours. what is the appropriate inference procedure to be used to estimate how much longer the battery lasts in their model 10 phone than in their model 9 phone?\no t confidence interval for a mean\no z confidence interval for a proportion\no t confidence interval for a difference in means\no z confidence interval for a difference in proportions

Answer

Brief Explanations:

We are comparing the mean battery - life of two different phone models (model 10 and model 9). Since we are dealing with means of two independent samples and the population standard deviation is unknown (we only have sample standard deviations), the appropriate inference procedure is a t - confidence interval for a difference in means.

Answer:

t confidence interval for a difference in means