Question

In: Statistics and Probability

The time it takes workers to finish cleaning is normally distributed with a mean of 73.27...

The time it takes workers to finish cleaning is normally distributed with a mean of 73.27 minutes and a standard deviation of 7.04 minutes. If 13 workers are randomly selected, what is the probability the average time it takes them to finish cleaning is more than 73 minutes?

Solutions

Expert Solution

Here in this scenario it is given that the time it takes workers to finish cleaning is normally distributed with a mean of 73.27 minutes and a standard deviation of 7.04 minutes.

Now If we 13 workers are randomly selected then the probability the average time it takes them to finish cleaning is more than 73 minutes is given below,

Here note that the X fallowing the normal distribution with mean mu and sigma then,

Sampling Distribution samples mean xbar follows the normal with mean mu and sigma /√n.

The probability is calculated using Standerd normal distribution sampling Distribution for sample mean is calculated as below,

P(Xbar > 73) =

The probability is calculated using Standerd normal z-table.

The probability that the average time of 13 selected it takes them to finish cleaning is more than 73 minutes is 0.555.

Thank you.


Related Solutions

The time that is takes to traverse the Bitfrost Bridge into Asgard is normally distributed with...
The time that is takes to traverse the Bitfrost Bridge into Asgard is normally distributed with a mean of 3.58 minutes. If 67.72% of Asgardains take longer than 3.10 minutes to cross the bridge, what is the value of the standard deviation of the times?
The time it takes to complete the assembly of an electronic component is normally distributed with...
The time it takes to complete the assembly of an electronic component is normally distributed with a standard deviation of 4.5 minutes. If a random of 20 components is selected, what is the probability that the standard deviation for the time of assembly of these units is less than 3.0 minutes?
The time for a professor to grade an exam is normally distributed with a mean of...
The time for a professor to grade an exam is normally distributed with a mean of 12.6 minutes and a standard deviation of 2.5 minutes. 1. Compute Z-score if it took the professor 15 minutes to grade an exam 2. What is the probability that a randomly selected exam will require between 12 and 15 minutes to grade? 3. What is the probability that a randomly selected exam will require less than 15 minutes to grade?
The weekly wages of steel workers at a steel plant are normally distributed with a mean...
The weekly wages of steel workers at a steel plant are normally distributed with a mean weekly wage of $940 and a standard deviation of $85. There are 1540 steel workers at this plant. a) What is the probability that a randomly selected steel worker has a weekly wage i) Of more than $850? ii) Between $910 and $960? b) What percentage of steel workers have a weekly wage of at most $820? c) Determine the total number of steel...
The time it takes to bake a Betty Crocker Supermoist Fudge Cake is normally distributed with...
The time it takes to bake a Betty Crocker Supermoist Fudge Cake is normally distributed with a mean of 45 minutes and a variance of 26 minutes^2. Let baking time, in minutes, be represented by random variable X. P(x1 < X < 49) = 0.0910. Find x1 (in minutes).
The time it takes to drive from Orangeville to the Vaughan Mills Mall is normally distributed...
The time it takes to drive from Orangeville to the Vaughan Mills Mall is normally distributed with a mean of 52 minutes and standard deviation of 5 minutes. What intervals could you estimate, using the knowledge from this activity, that do not include the mean as a max or min? For example,   is an interval we could estimate. However, it includes the mean as the maximum of the interval. Another example is  as an example of a probability interval that we know...
The actual time it takes to cook a ten pound turkey is a normally distributed. Suppose...
The actual time it takes to cook a ten pound turkey is a normally distributed. Suppose that a random sample of 19 ten pound turkeys is taken. Given that an average of 2.9 hours and a standard deviation of .24 hours was found for a sample of 19 turkeys, calculate a 95% confidence interval for the average cooking time of a ten pound turkey.
1. The incubation time for a breed of chicks is normally distributed with a mean of...
1. The incubation time for a breed of chicks is normally distributed with a mean of 28 days and standard deviation of approximately 1 day. Look at the figure below and answer the following questions. If 1000 eggs are being incubated, how many chicks do we expect will hatch in the following time periods? (Note: In this problem, let us agree to think of a single day or a succession of days as a continuous interval of time. Assume all...
1. The incubation time for a breed of chicks is normally distributed with a mean of...
1. The incubation time for a breed of chicks is normally distributed with a mean of 28 days and standard deviation of approximately 1 day. Look at the figure below and answer the following questions. If 1000 eggs are being incubated, how many chicks do we expect will hatch in the following time periods? (Note: In this problem, let us agree to think of a single day or a succession of days as a continuous interval of time. Assume all...
Suppose that the waiting time for a bus is normally distributed with a mean of 5...
Suppose that the waiting time for a bus is normally distributed with a mean of 5 minutes and a standard deviation of 2.5 minutes. (a) Find the probability that the waiting time for the bus is between 3 minutes and 7 minutes. (b) If you randomly choose 4 passengers, find the sampling distribution of their average waiting time. Please indicate shape, mean and standard deviation. (c) For the randomly selected 4 passengers, find the probability that their average waiting time...
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT