The mean and the standard deviation of the life time of a type of a solar panel is assumed to be 2500 weeks and 200 weeks respectively. Assume that the life time of solar panels follows a normal distribution. At what length of life should the guarantee be set in order for 98 per cent of solar panels to be found satisfactory? (no decimal: round up to the next integer value)
The mean and the standard deviation of the life time of a type of a solar...
The average life of a certain type of small motor is 10 years with a standard deviation of 2 years. The manufacturer replaces free all motors that fail while under guarantee. If she is willing to replace only 3% of the motors that fail, how long a guarantee should be offered? Assume that the lifetime of a motor follows a normal distribution.
O: le, the mean commute time to work was 33.5 minutes and the standard deviation was 7.3 In a random sample of 8 peop minutes A 90% confidence interval using the to work, it was found that the population standard deviation is 9 6 minutes Find the margin of error and construct a 90% confidence interval using the standard normal distribution with the appropriate calculations for a standard deviation that is known. Compare the results t-distribution was calculated to be...
The average healing time of a certain type of incision is 192 hours, with standard deviation of 30 hours. What percentage of the people having this incision would heal in 7 days or less? Assume a normal distribution. Click the icon to view the area under the standard normal curve table. % of people having this incision should heal in 7 days or less. (Type an integer or decimal rounded to the nearest hundredth as needed.)
The life of an automobile battery is known to follow normal distribution with a mean of 2000 days and a standard deviation of 200 days. (a) Find the percentage of batteries which fail before 1500 days. (b) What should be the guarantee period to be specified by the manufacturer so that the manufacturer will encounter only 10 percent failures of the battery?
A certain type of refrigerator has a length of life that is approximately normally distributed with a mean of 4.8 years and a population standard deviation of 1.3 years. What period of time should the manufacturer give as a guarantee if it is willing to replace only 1% of the machines?
Given a standardized normal distribution (with a mean of 0 and a standard deviation of 1) complete parts (a) through (d) below. Click here to view page 1 of the cumulative standardized normal distribution table, Click here to view page 2 of the cumulative standardized normal distribution table. a. What is the probability that Z is between 1.57 and 1.83? - The probability that Z is between 1.57 and 1.83 is (Round to four decimal places as needed.) particular train...
A sample mean, sample size, population standard deviation, and confidence level are provided. Use this information to complete parts (a) through (c) x = 33, n = 25, C = 6, confidence level = 90% Click here to view page 1 of the standard normal distribution table. Click here to view page 2 of the standard normal distribution table a. Use the one-mean z-interval procedure to find a confidence interval for the mean of the population from which the sample...
The average life of a certain type of small motor is 10 years with a standard deviation of 2 years. The manufacturer replaces free all motors that fail while under guarantee. If she is willing to replace 3% of the motors that fail, how long a guarantee (in years) should she offer? You may assume that the lives of the batteries are normally distributed. A properly labeled figure of the normal distribution curve and x and z values is required...
In a random sample of 8 people, the mean commute time to work was 33.5 minutes and the standard deviation was 7.4 minutes. A 98% confidence interval using thet-distribution was calculated to be (25.7,41.3). After researching commute times to work, it was found that the population standard deviation is 8.6 minutes. Find the margin of error and construct a 98% confidence interval using the standard normal distribution with the appropriate calculations for a standard deviation that is known. Compare the...
Part B A sample mean, sample size, population standard deviation, and confidence level are provided. Use this information to complete parts (a) through (c) below. x=52, n = 13,0-6, confidence level = 99% Click here to view page 1 of the standard normal distribution table. Click here to view page 2 of the standard normal distribution table. a. Use the one mean z-interval procedure to find a confidence interval for the mean of the population from which the sample was...