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How many strings of eight uppercase English letters are there
a) that start with X, if no letter can be repeated?
How long would it take 4.0 x 10²⁰ atoms to decay to 1.0 x 10¹⁹ atoms if their half-life was 14.7 years?
A radioactive substance with a half-life of 3.0 days has an initial activity of 0.24Ci. What is its activity after 6.0 days?
A radioactive sample has a half-life of 10 min. What fraction of the sample is left after 40 min.
If a 4.0x10¹⁸ atoms decay with a life of 2.3 years, how many are remaining after 3.7 years?
Find the energy of incident photons if a 430-nm violet light is incident on a calcium photoelectrode with a work function of 2.71 eV.
Determine the work function when a 180-nm light is used in an experiment with an unknown metal, the measured photocurrent drops to zero at potential -0.08V.
Find the electric potential at a distance 0f 8cm from 7.58pC charge.
Parameter, null hypothesis in symbol, alternative hypothesis in symbol, directional or non directional, level of significance,.
1. A company which produces batteries claims that the life expectancy of their batteries is 90 hours. In order to test the claim, a consumer interest group tested a random sample of 40 batteries. The test resulted to a mean life expectancy of 87 hours. Using a 0.05 level of significance, can it be concluded that the life expectancy of their batteries is less than 90 hours? Assume that the population standard deviation is known to be 10 hours.
A bank Manager wishes to provide a prompt service to customers at the bank derive up windows. The bank currently can serve up to 10 customers per 15 minutes period without significant delay. The average arrival rate is 7 customers per 15 minutes period. Let 𝑥 be the number of customers arriving per 15 minutes period. Assuming that 𝑥 has a Poisson distribution. a) Find
i. The probability that 10 customers will arrive in a particular 15 minutes period. ii. The probability that 10 or fewer customers will arrive in a particular 15 minutes period.
b) Find the probability that there will be a significantly delay at the derive up window. That is to find the probability that more than 10 customers will arrive during a particular 15 minutes period.
