# Biology Forums - Study Force

## Science-Related Homework Help Statistics and Probability Topic started by: RioNii on Jan 31, 2023

 Title: Probability Distribution Post by: RioNii on Jan 31, 2023 Instructions: a) Identify the type of probability distribution shown in the problem: binomial, hypergeometric, poisson etc. b) Identify the given in the problem. c) Solve for the probability.4) The length of time, L hours, that a phone will work before it needs charging is normally distributed with a mean of 100 hours and standard deviation of 15 hours. Find the probability that a randomly selected phone will work greater than 127 hours before it needs charging. Title: Re: Probability Distribution Post by: bio_man on Jan 31, 2023 This is a normal distribution model:$$f\left(x\right)=\frac{1}{\sigma \sqrt{2\pi }}e^{-0.5\left(\frac{x-\mu }{\sigma }\right)^2}$$QuoteThe length of time, L hours, that a phone will work before it needs charging is normally distributed with a mean of 100 hours and standard deviation of 15 hours. Find the probability that a randomly selected phone will work greater than 127 hours before it needs charging.$$\mu$$ = 100$$\sigma$$ = 15x = 127$$z=\frac{127-100}{15}=\frac{27}{15}$$P(x>127) = 1 - P(x≤127)= 1 - (27/15)Using your calculator:normalcdf(-999,127,100,5)= 1 - .964 = .036