|Mean and standard deviation of working life data of bulbs produced in a factory are 1406 and 153 hours. With the renovation to be carried out in the factory, it is expected that the bulb working life will be greater than 1406 hours. After a test with a small sample of 15 renovation elements, the average working life values are given in the Table. According the test, is it appropriate to perform this renovation? During the calculation, assume that; a) the working life is normally distributed b) the population standard deviation is unknown (use t-distribution). For both take the significance level as 0.10. X 1200 1800 | 1100 | 1650 1580 1610 | 1695 1490| 1400 1350 1200 | 1450 | 1500 | 1480| 1300
Inverse Normal Distribution
The method used for finding the corresponding z-critical value in a normal distribution using the known probability is said to be an inverse normal distribution. The inverse normal distribution is a continuous probability distribution with a family of two parameters.
Mean, Median, Mode
It is a descriptive summary of a data set. It can be defined by using some of the measures. The central tendencies do not provide information regarding individual data from the dataset. However, they give a summary of the data set. The central tendency or measure of central tendency is a central or typical value for a probability distribution.
Z-Scores
A z-score is a unit of measurement used in statistics to describe the position of a raw score in terms of its distance from the mean, measured with reference to standard deviation from the mean. Z-scores are useful in statistics because they allow comparison between two scores that belong to different normal distributions.
Step by step
Solved in 4 steps
