Mathematics, 21.12.2019 00:31 BookiesBaby8533

An article in the november 1983 consumer reports compared various types of batteries. the average life-times of duracell alkaline aa batteries and eveready energizer alkalineaa batteries were given as 4.1 hours and 4.5 hours, respectively. suppose these are thepopulation average lifetimes. a.let¯xbe the sample average lifetime of 100 duracell batteries and¯ybe the sampleaverage lifetime of 100 eveready batteries. what is the mean value of¯x-¯y(i. e.,where is the distribution of¯x-¯ycentered)? how does your answer depend on thespecified sample sizes? e(¯x-¯y) =e(¯x)-e(¯y) =μ¯x-μ¯y=μx-μy= 4.1-4.5 =-0.4the mean value of¯x-¯ydoes not depend on the sample size. b.suppose the population standard deviations of lifetime are 1.8 hours for duracellbatteries and 2.0 hours for eveready batteries. with the sample sizes given in part(a), what is the variance of the statistic¯x-¯yand what is the standard deviation? v(¯x-¯y)=v(¯x) +v(¯y) =σ2¯x-σ2¯y=σ2x/√m-σ2y/√n=(1.8)2/100 + 22/100 =0.0724qv(¯x-¯y)=0.2691

Answers: 1

Show answers

Another question on Mathematics

Mathematics, 21.06.2019 13:30

12. decide whether each statement is always true, sometimes true, or never true. a. when corresponding points of an original figure and its reflection are connected, the resulting segments are all perpendicular to the line of reflection. b. when a point is reflected over a horizontal line, the y-coordinate of the point stays the same. answer both questions and explain

Answers: 2

Answer

Mathematics, 21.06.2019 13:30

Akitchen floor is made up of tiles that are in the shape of the triangle shown there are 40 tiles on the kitchen floor what is the total area of the floor

Answers: 2

Answer

Mathematics, 21.06.2019 18:30

According to the 2008 u.s. census, california had a population of approximately 4 × 10^7 people and florida had a population of approximately 2 × 10^7 people. which of the following is true? a. the population of florida was approximately two times the population of california. b. the population of florida was approximately twenty times the population of california. c. the population of california was approximately twenty times the population of florida. d. the population of california was approximately two times the population of florida.

Answers: 1

Answer

Mathematics, 21.06.2019 21:00

Ariana starts with 100 milligrams of a radioactive substance. the amount of the substance decreases by 20% each week for a number of weeks, w. the expression 100(1−0.2)w finds the amount of radioactive substance remaining after w weeks. which statement about this expression is true? a) it is the difference between the initial amount and the percent decrease. b) it is the difference between the initial amount and the decay factor after w weeks. c) it is the initial amount raised to the decay factor after w weeks. d) it is the product of the initial amount and the decay factor after w weeks.

Answers: 1

Answer

You know the right answer?

An article in the november 1983 consumer reports compared various types of batteries. the average li...

Questions