An investigation of the relative merits of two kinds to flashlight batteries showed that a random sample of 100 batteries of brand X lasted on the average 36.5 hours with a standard deviation of 1.8 hours, while a random sample of 80 batteries of brand Y, lasted on the average 36.8 hours with a standard deviation of 1.5 hours. Use a level of significance of 0.05 to test whether the observed difference between the average life times is significant.

Q: Light globes produced by a manufacturing company have had a life expectancy of 1350 hours. Because…

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Q: An article presents the results of a study in which the weights of 295 eggs from 27 week-old…

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Q: A shareholders' group is lodging a protest against your company. The shareholders group claimed that…

A: We want to find the test statistic and p value

Q: Systolic blood pressure (mm Hg) was determined for each individual in a random sample of fifty…

A: Given, sample size, n = 50 Sample mean -x = 207.8 Sample standard deviation s = 10.9 significance…

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A: Empirical rule :  According to empirical rule ,  68% of data falls within the first standard…

Q: t the main campus of a large state university recieves daily requests to fix small and medium-sized…

A: According to the empirical rule, for a normal distribution, 68%, 95%, and 99.7% of the values lie…

Q: The physical plant at the main campus of a large state university recieves daily requests to replace…

A: We have given that the random variable X i.e. lightbulb is normally distributed with mean 59 and…

Q: A construction company was approached by a manufacturer of rechargeable batteries for cordless…

A: Null and alternative hypotheses: The investigator is interested to test whether the average life of…

Q: A company that makes hotel toilets claims that its new pressure-assisted toilet reduces the average…

A: x1=1.64x2=1.09d=0.5s1=0.18s2=0.29n1=30n2=30​​​

Q: A new iron supplement is being tested to see if it can increase the mean of ferritin levels. Study…

A: Given Information: Group 1: Sample size n1=30 Sample mean x¯1=43 Sample standard deviation s1=13…

Q: A laboratory claims that the mean sodium level, u , of a healthy adult is 141 mEq per liter of…

A: Null hypothesis: H0: μ = 141. Alternative hypothesis: H1: μ ≠141. Here, the sample mean, x-bar is…

Q: The average amount of time it takes for couples to further communicate with each other after their…

A: We have given that,  Hypothesized mean = 2.28 . Sample mean = 2.4 . Standard deviation = 0.558 .…

Q: ppose that shoe sizes of American women have a bell-shaped distribution with a mean of 8.42 and a…

A: Given data,Mean μ=8.42sd    σ=1.52P(6.9<X<9.94)=?

Q: A large national study conducted in 2004 found that the mean systolic blood pressure for males aged…

A: From the provided information, Sample size (n) = 200 Sample mean (x̅) = 136 Standard deviation (s) =…

Q: he blood platelet counts of a group of women have a bell-shaped distribution with a mean of 253.8…

A: Given data,Mean μ=253.8sd    σ=61.7P(68.7<X<438.9)=?

Q: A person read that the average number of hours and adult sleeps on Friday night to Saturday morning…

A: Hey, since there are multiple subparts posted, we will answer first three subparts. If you want any…

Q: A survey conducted in Mega Manila with a sample of 350 gasoline stations found that the price…

A: According to the empirical rule [Also known as 68-95-99.7 rule]. Therefore, the probability that…

Q: The mean life time of a sample of 400 fluoroscent light bulbs produced by a company is found to be…

A:

Q: A study of the operation of a parking garage showed that, in the past, the average parking time was…

A: The hypotheses can be constructed as: Null hypothesis: H0: µ = 220 Alternative hypothesis: H1: µ ≠…

Q: A researcher knew that before cell phones, a person made on average 3.2 calls per day. He believes…

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Q: A manufacturer of plasma has determined that the televisions require servicing after a mean of 67…

A: Let x be the length of warranty should be offered which follows normal distribution with mean 67 and…

Q: Simple random samples of high interest (8.9%) and low interest (6.3%) mortgages were obtained. For…

A: Let μ1 be the population mean mean FICO score borrowers with a high interest mortgage, and μ2 be the…

Q: A particular brand of tires claims that its deluxe tire averages at least 50,000 miles before it…

A: Method: Use z test statistic to calculate the test value

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A: Obtain the 95% confidence interval for the difference between two means.   The 95% confidence…

Q: What can be concluded at the the αα = 0.10 level of significance?

A: Given that  The average American consumes 86 liters of alcohol per year Population mean (μ) = 86…