Company XYZ know that replacement times for the DVD players it produces are normally distributed with a mean of 8.3 years and a standard deviation of 2 years. Find the probability that a randomly selected DVD player will have a replacement time less than 3.3 years? P(X < 3.3 years) =  Enter your answer accurate to 4 decimal places. Answers obtained using exact z-scores or z-scores rounded to 3 decimal places are accepted. If the company wants to provide a warranty so that only 1.6% of the DVD players will be replaced before the warranty expires, what is the time length of the warranty? warranty =

The average score that can be obtained on a standardized test at your school is114with a standard deviation of 16. You are a reporter for the school newspaper and you want to know if thetypical deviation, o,Student athletes are different. To find out, he surveys a random sample of 18student athletes and determines that for the sample, the mean score is112with a standard deviation of12.If we assume that the scores that the student athletes obtained follow an approximately normal distribution, is there enough evidence to conclude, at the level of significance of 0.05, which standard deviation is higher among student athletes? Perform a two-tailed test. Then complete the following. Carry intermediate calculations to three or more decimal places. (If necessary, you can refer to a list of formulas .) (to) Formulate the null hypothesish and the alternative hypothesish 1' ho: 0 0 (b) (c) (d) h ! 1 0 Determine which type of test statistic to use. (Choose an option) Find the value of the test…

The life of light bulbs is distributed normally. The standard deviation of the lifetime is 25 hours and the mean lifetime of a bulb is 550 Find the probability of a bulb lasting for at least 605 hours (round your answer to four decimal places)

Females have pulse rates that are normally distributed with a mean of 74 beats per minute and a standard deviation of 12.5 beats per minute.  If 16 adult female are randomly selected, find the probability that their pulse rates are less than 70 beats per minute. Express your answer as a percent rounded to 2 decimal places.