SOLUTION: The Wall Street Journal reported that approximately 25% of the people who are told a product is improved will believe that it is, in fact, improved. The remaining 75% believe that

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Question 375852: The Wall Street Journal reported that approximately 25% of the people who are told a product is improved will believe that it is, in fact, improved. The remaining 75% believe that this is just hype (the same old thing with no real improvement). Suppose a marketing study consists of a random sample of twelve people who are given a sales talk about a new, improved product.
Compute the mean and standard deviation of this probability distribution.
Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
Find the probability for the number of believers from 0 to 12.
P%280%29=1%2A%280.75%29%5E12%2A%280.25%29%5E0=0.03168
P%281%29=12%2A%280.75%29%5E11%2A%280.25%29%5E1=0.12671
P%282%29=66%2A%280.75%29%5E10%2A%280.25%29%5E2=0.23229
P%283%29=220%2A%280.75%29%5E9%2A%280.25%29%5E3=0.25810
P%284%29=495%2A%280.75%29%5E8%2A%280.25%29%5E4=0.19358
P%285%29=792%2A%280.75%29%5E7%2A%280.25%29%5E5=0.10324
P%286%29=924%2A%280.75%29%5E6%2A%280.25%29%5E6=0.04015
P%287%29=792%2A%280.75%29%5E5%2A%280.25%29%5E7=0.01147
P%288%29=495%2A%280.75%29%5E4%2A%280.25%29%5E8=0.00239
P%289%29=220%2A%280.75%29%5E3%2A%280.25%29%5E9=0.00035
P%2810%29=66%2A%280.75%29%5E2%2A%280.25%29%5E10=0.00004
P%2811%29=12%2A%280.75%29%5E1%2A%280.25%29%5E11=0.00000
P%2812%29=1%2A%280.75%29%5E0%2A%280.25%29%5E12=0.00000
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mu=sum%28x%2AP%28x%29%2C0%2C12%29
mu=3
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VAR=sum%28%28x-mu%29%5E2%2AP%28x%29%2C0%2C12%29
VAR=2.25
sigma=sqrt%28VAR%29=1.5%29
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