The lifetimes of lightbulbs of a particular type are normally distributed with a mean of 400 hours and a standard deviation of 10 hours. What percentage of the bulbs have lifetimes between 380 hours and 420 hours?     99.7%     95%     68%     84%

Q: Find the replacement time that separates the top 82% from the bottom 18%. Group of answer choices…

A: Given : Population Mean,μ = 9.5 Population Standard Deviation,σ = 1.8 X follows…

Q: Use the Empirical Rule. The mean speed of a sample of vehicles along a stretch of highway is 69…

A: Solution:The empirical rule for any normal distribution is given below.68% of the observations fall…

Q: A normally distributed data set has a mean of 0 and a standard deviation of 2. What is the percent…

A:

Q: The population standard deviation           a. is always the same as the sample standard deviation.…

A: Solution: The standard deviation explains the dispersion in the data. The population standard…

Q: The average age of our class is 22.3 years.  The standard deviation is 4.7 years.  If the variable…

A: Solution: Let X be the average age of class has normal  distribution  with mean μ=22.3 years and…

Q: Identify the data value corresponding to the indicated percentile. The heights of women are normally…

A: According to the provided information,

Q: A company that manufactures tires produces a tire that has a average life span of 65,000 kilometers…

A: We have to find given probability.

Q: A particular fruit's weights are normally distributed, with a mean of 218 grams and a standard…

A: Given: μ=218 and σ=40. Also,PZ>z=13%⇒PZ>z=0.13⇒1-PZ≤z=0.13⇒PZ≤z=0.87

Q: A particular fruit's weights are normally distributed, with a mean of 486 grams and a standard…

A:

Q: A study found out that for a particular area, the average income per family is $24596 and the…

A: Solution

Q: minutes. What percentage of his commutes will be between 13 and 26 minutes, to the nearest tenth?

A: Let X be the random variable that amount of time to arrive. Given that, X~N(μ=23,σ=5)

Q: a particular fruit weights are normally distributed, with a mean of 787 grams and a standard…

A: Let us define X=Random variable of the fruit’s weight with mean=787 grams and standard deviation= 9…

Q: A company produces steel rods. The lengths of the steel rods are normally distributed with a mean of…

A: It is given that the mean is 116.7 and the standard deviation is 2.

Q: Salespeople for a solar technology company have average annual sales of $400,000, with a standard…

A:

Q: A particular fruit's weights are normally distributed, with a mean of 305 grams and a standard…

A: Given: Formula: Let "X" be the weight of fruits in grams.

Q: 15

A: Given: μ=1650, σ=320 The corresponding z-values needed to be computed are: The probability of the…

Q: Suppose that the distance of fly balls hit to the outfield (in baseball) is normally distributed…

A:

Q: The body temperatures of adults are normally distributed with a mean of 98.6° F and a standard…

A: Percentile:The percentile is the proportion of data lying below a certain value. For example, 56…

Q: A particular fruit's weights are normally distributed, with a mean of 230 grams and a standard…

A: The provided information is:

Q: The amount of bleach a machine pours into bottles has a mean of 36oz. with a standard deviation of…

A: The objective of the question is to find the mean of the sampling distribution of the sample mean.…

Q: Consider the variable, type of birth control practiced (e.g., an IUD, condoms, none, etc). Which…

A:

Q: A particular fruit's weights are normally distributed, with a mean of 621 grams and a standard…

A: It is given that the fruits weights follow normal distribution with mean 621 and standard deviation…

Q: The weights for a population of North American raccoons have a bell shaped frequency curve with a…

A:

Q: A particular fruit's weights are normally distributed, with a mean of 464 grams and a standard…

A: Let "x" be the weight of the fruit in grams. Sketch the normal curve and shade the area of 0.18…

Q: The birth weights of newborn elephants are Normally distributed with a mean of 160 pounds and a…

A:

Q: A particular fruit’s weights are normally distributed, with a mean of 712 grams and a standard…

A: Given,mean(μ)=712  gramsstandard deviation(σ)=28  grams

Q: LED lamp has a mean usage of 750 hours with standard deviation of 50 hours. If LED lamp usage is…

A: Provided information is,  A LED lamp has a mean usage of 750 hours with standard deviation of 50…

Q: The middle 50% of the heights are between what two values? Round to one decimal place.

A: Here Given, Assume that women have heights that are normally distributed with a mean of 63.6 inches…

Q: A particular fruit's weights are normally distributed, with a mean of 620 grams and a standard…

A: Probability distributions are of two types, discrete and continuous distributions. Normal…

Q: population, it was found that the diastolic blood pressure is normally distributed with a mean 81.5…

A:

Q: Suppose the heights of women at a college are approximately Normally distributed with a mean of 65…

A: The objective of this question is to find the height that corresponds to the 40th percentile in a…

Q: Identify the data value corresponding to the indicated percentile. The amount of sleep an adult gets…

A: The normal distribution:A continuous random variable X is said to follow normal distribution with…

Q: To assess the air quality in a surgical suite, the presence of colony-forming spores per cubic meter…

A: {12,24,30}