week 4 hw 2

.docx

School

American Public University *

*We aren’t endorsed by this school

Course

302

Subject

Statistics

Date

Jan 9, 2024

Type

docx

Pages

Uploaded by ballinger54 on coursehero.com

n 1 1 Find the area under the standard normal distribution to the left of z = -1.05. Round answer to 4 decimal places. Answer: ___.1469 ___ uestion 1 feedback el, M.S.DIST(-1.05,TRUE) on 2 0 / Find P(Z ≥ 1.8). Round answer to 4 decimal places. Answer: ___.0790 ___ (0.0359, .0359) uestion 2 feedback el, RM.S.DIST(1.8,TRUE) on 3 0 / The size of fish is very important to commercial fishing. A study conducted in 2012 found the length of Atlantic cod caught in nets in Karlskrona to have a mean of 49.9 cm and a standard deviation of 3.74 cm (Ovegard, Berndt & Lunneryd, 2012). Assume the length of fish is normally distributed. What is the length in cm of the longest 15% of Atlantic cod in this area? Round answer to 2 decimal places. Answer: ___53.79 ___ (53.78) uestion 3 feedback t 15% is the upper 85%, 1 - .15 = .85 el, M.INV(0.85,49.9,3.74) on 4 1 / Which type of distribution does the graph illustrate?

Uniform Distribution Right skewed Distribution Normal Distribution Poisson Distribution Question 5 0 / 1 point The manufacturer of a new compact car claims the miles per gallon (mpg) for the gasoline consumption is mound-shaped and symmetric with a mean of 26.3 mpg and a standard deviation of 11.2 mpg. If 30 such cars are tested, what is the probability the average mpg achieved by these 30 cars will be greater than 28? Answer: ___ Round your answer to 4 decimal places as necessary. For example, 0.1357 would be a legitimate entry. Make sure you include the zero before the decimal. ___ Answer: .2029 (0.2029) Hide question 5 feedback This is a sampling distribution problem with μ = 26.3. σ = 11.2, and sample size n = 30. New SD = 11.2/SQRT(30) = 2.044831 P(x > 28) = 1 - NORM.DIST(28, 26.3, 2.044831, TRUE)

n 6 1 Suppose that the longevity of a light bulb is exponential with a mean lifetime of eight years. Find the probability that a light bulb lasts between six and ten years. 0.1175 0.1859 9.6318 0.3034 0.3682 Hide question 6 feedback P( 6 < x < 10) P(x < 10) - P( x < 6) In Excel, =EXPON.DIST(10,1/8,TRUE)-EXPON.DIST(6,1/8,TRUE) n 7 1 The average lifetime of a set of tires is three years. The manufacturer will replace any set of tires failing within two years of the date of purchase. The lifetime of these tires is known to follow an exponential distribution. What is the probability that the tires will fail within two years of the date of purchase? 0.8647 0.2212 0.4866 0.9997 Hide question 7 feedback P(x < 2) In Excel, =EXPON.DIST(2,1/3,TRUE) n 8 1

Suppose that the longevity of a light bulb is exponential with a mean lifetime of eight years. Seventy percent of all light bulbs last at least how long? 0.1175 0.1859 9.6318 0.3034 0.3682 Hide question 8 feedback For the 70th percentile use .70 in the equation and the rate of decay is 1/8 − (1−.70)18 �� n 9 1 The average lifetime of a certain new cell phone is three years. The manufacturer will replace any cell phone failing within two years of the date of purchase. The lifetime of these cell phones is known to follow an exponential distribution. What is the median lifetime of these phones (in years)? 5.5452 1.3863 0.1941 2.0794 Hide question 9 feedback Median Lifetime is the 50th percentile. Use .50 in the equation and the rate of decay is 1/3 − (1−.5)13 �� n 10 1 Miles per gallon of a vehicle is a random variable with a uniform distribution from 25 to 35. The probability that a random vehicle gets between 28 and 33 miles per gallon is: Answer: (Round to two decimal place) ___0.50 ___ uestion 10 feedback

Your preview ends here

Eager to read complete document? Join bartleby learn and gain access to the full version