SOLUTION: Hello! I am doing probability distributions and finding the mean and standard deviation of a binomial distribution at the moment and have a multiple step question i need help on.

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Question 1028488: Hello!
I am doing probability distributions and finding the mean and standard deviation of a binomial distribution at the moment and have a multiple step question i need help on.
It is: Find the mean and standard deviation for each of the following binomial random variables.
A.) the number of tails seen in 50 tosses of a quarter
B.) the number of aces seen in 100 draws from a well-shuffled bridge deck( without replacement)
C.) the number of cars found to have unsafe tires among the 400 cars stopped for inspection. Assume 6% of all cars have one or more unsafe tires.
D.) The number of melon seeds that germinate when a pack of 50 seeds is planted. The probability of germination is .88.
I know how to get to the binomalpdf on the calculator, i am just having trouble knowing what information to put in where. Any help would be greatly appreciated. Thank you!!!
Answer by robertb(5830) (Show Source):
You can put this solution on YOUR website!
A.) The number of tails seen in 50 tosses of a quarter.
If the quarter is unbiased, then the mean should be 50*0.5 = 25. Variance should be 50*0.5*0.5 = 12.5, and hence standard deviation is approximately.
B.) The number of aces seen in 100 draws from a well-shuffled bridge deck(without replacement).
Assuming an infinite population (so that the non-replacement is immaterial), the mean is , while the variance is , hence the standard deviation is approximately.
C.) The number of cars found to have unsafe tires among the 400 cars stopped for inspection. Assume 6% of all cars have one or more unsafe tires.
Mean would be , and standard deviation is approximately.
D.) I leave this up to you.