A sample of 150 brand A light bulbs showed a mean lifetime of 1392 hours and a standard deviation of 120 hours. A sample of 100 brand B light bulbs showed a mean lifetime of 1232 hours and a standard deviation of 80 hours. Which of the following is the 95% confidence interval for the difference of the mean lifetimes of the populations of brands A and B? a. (144.2,  175.8) b. (139.2,  180.8) c. (135.2,  184.8) d. (147.4,  172.6) e. (127.4,  192.6)

Q: A study of 36 golfers showed that their mean score at The Links at Arundel was 83.  The standard…

A: n=sample size= 36 X¯=sample mean=83σ=sample standard deviation=5 So the point estimate=X=83   Since…

Q: A sample of the reading scores of 40 foundatin students has a mean marks of 25. If the standard…

A:

Q: The average height of students at a random place from an SRS of 12 students gave a standard…

A: The sample size is 12 and sample standard deviation is 2.5.

Q: In a mid-size company, the distribution of the number of phone calls answered each day by each of…

A:

Q: A sample of 25 bottles of orange juice were measured and the sample standard deviation is 1.8…

A:

Q: A certain counselor wants to compare mean IQ scores for two different social groups. A random sample…

A: Given that    Sample sizes n1=13    , n2=11      Sample means X̄1=103      , X̄2=116      s1 =15…

Q: Calculate a 95% upper confidence bound for the mean of a normally distributed population using the…

A: given data  x¯ = 39316n = 14σ= 3276normal distribution 95% upper confidence bound = ?

Q: sample of 352 subscribers to Wired magazine shows the mean time spent using the Internet is 18.4…

A: Given data,n=352x=18.4s=6.8α=0.05df=n-1=351t-critical value is tc=1.967

Q: In a random sample of six people, the mean driving distance to work was 24.9 miles and the standard…

A: The sample size: n=6 Sample mean: x¯=24.9 miles Standard deviation: s=7.9 Confidence level: C=0.99…

Q: Suppose that weights of 3200 registered female great Danes in the United States are distributed…

A: Using normalised probability and z table

Q: were found to have an average weight of 9.7 ounces with a sample standard deviation is 0.20. Find…

A: As the population standard deviation is not known, we will use t distribution. Degrees of freedom…

Q: population has a standard deviation of 18 on average how much difference should exist between the…

A: A population has a standard deviation of 18.

Q: mean of 50 ounces and a standard deviation of 8.81 ounces. 8 homes with children are surveye Let X =…

A: As the population distribution is normal, it can be said that the distribution of the sample with…

Q: (a) The life spans of three randomly selected tires are 35,000 miles, 36,000 miles, and 31,000…

A: The provided information is, µ=33000 miles,σ=2250 miles a. The life span of three randomly selected…

Q: A report said that the average blood pressure is  130.71  for a sample of  37  white males aged  35…

A:

Q: A study of 40 English composition professors showed that they​ spent, on​ average, 12.6 minutes…

A:

Q: (b) The life spans of three randomly selected tires are 29,700 miles, 34,300 miles, and 32,000…

A: (b) The one standard deviation limits are, μ-σ,μ+σ=32000-2300,32000+2300=29700,34300 The two…

Q: Patients at the outpatient surgical center in Braintree, MA have an average recovery time of 14 days…

A: Given that : Mean = 14 days S. D = 3 days P(z < y) = 62%  Let y be the  raw score.  By using…

Q: A fire department in a rural county reports that its response time to fires is approximately…

A: Consider that a random variable x, defines the response time to fires.

Q: State the null and alternative hypotheses. Using α = 0.01 level of significance, what is your…

A: 1. Let μ denotes the mean credit card balance for undergraduate students. The claim of the test is…

Q: use this to find a 95% confidence interval for the mean height of all red maple trees

A: The sample size is n = 146 Sample mean = 59 And sample SD = 12 Since the sample size is large then…

Q: A 95% confidence interval for the mean was computed with a sample of size 90 to be (16,22). a. What…

A:

Q: Find the upper boundary of the 90% confidence interval for the variance for the lifetimes of…

A:

Q: A sample of 352 subscribers to Wired magazine shows the mean time spent using the Internet is 18.4…

A: Given -  Sample size, n = 352 Mean time spent, x=18.4 hoursStandard deviation, σ=6.8 hours

Q: UCES LIGHT BULBS, BULB NORMAL DISTRIBUTION WITH A MEAN OF 800 HOURS AND A STANDARD DEVIATION OF 40…

A: Answer Calculation:1. Calculate the z-score using the formula:      where:   - is the value we want…

Q: A random sample of 20 students yielded a mean of 68,55 and standar deviation of 4,59 for scores on a…

A: Introduction:

Q: 186.5, 197.5) 187.3, 196.1) 188.5, 195.6) (189.5, 194.5)

A:

Q: A random sample of 110 Americans was asked how many hot dogs they eat each year.  The sample mean…

A:

Q: A sample of 50 students was taken from the local university. These students spent an average of R170…

A: Given information- Sample size (n) = 50 Mean x̅ = R170 Standard deviation (s) = R25.50 Significance…

Q: Suppose a sample of 30 LCC students are given an IQ test. The sample has a standard deviation of…

A: Given the following information- n=30s=12.24s2=149.82

Q: A random sample of high school students is used to estimate the mean time all high school students…

A: Solution: From the given information, a 99% confidence interval is 1.7 hours to 3.1 hours.

Q: A company manufactures LED light bulbs. The lifetime for these bulbs is 4,100 hours with a standard…

A:

Q: Suppose that another sample of resting heart rates for five Math students was obtained: 72, 68, 66,…

A: From the given data we want to know the data value .

Q: Find a 95% CI on the population standard deviation of speeds of drivers ticketed in a 55 mph zone…

A: Confidence interval population standard deviation :  A confidence interval is an statistical…

Q: Peter collects data on the music scores of 200 randomly selected concertos. The sample mean of this…

A: It is given that the mean is 85,252 and the standard deviation is 8,413.

Q: A statistician chooses 27 randomly selected dates, and when examining the occupancy records of a…

A: Givensample size(n)=27Variance(s2)=34.34conidence level=95%

Q: 13 squirrels were found to have an average weight of 790 grams with a sample standard deviation of…

A: Given that  n=13 , Mean=X̄=790 , Standard deviation=S=8.3 95% confidence interval

Q: Suppose scores on exams in Biology are normally distributed with an unknown population mean and a…

A: given data σ = 5.4n = 60 x¯ = 81find 90% ci for μ = ?

Q: Suppose that IQ scores have a bell-shaped distribution with a mean of 103103 and a standard…

A: Solution: Let X be the IQ score. From the given information, X follows normal distribution with mean…

Q: In 1970, adults who were 18 years or more had a mean systolic blood pressure (SBP) of 148 mm Hg.,…

A: Given that in 1970 adults who were 18 years or more had a mean systolic blood pressure (SBP) of 148…

Q: sample of 426 managers sent, on average 9.81, messages with a standard deviation of 14.41 messages.…

A: given data   sample size(n) = 426 sample standard deviation(s)  = 14.41construct 90% ci for σ.

Q: A study of 65 bolts of carpet showed that their average length was 78.2 yards. The standard…

A: Assume that confidence level is 99%. Here, sample size is 65. Sample mean = 78.2. Standard deviation…

Estimation

A new framework of data analysis where the new statistical methods are used for interpreting the results and analyzing the data is known as estimation in statistics.