Academic Integrity: tutoring, explanations, and feedback — we don’t complete graded work or submit on a student’s behalf.

A recent cbs news survey reported that 57% of adults felt the U.S. Treasury shou

ID: 3133140 • Letter: A

Question

A recent cbs news survey reported that 57% of adults felt the U.S. Treasury should continue making pennies. http://ezto Homework 4: Chapter 6 zon.com-Online Sh... A recent CBS News survey reported that 57% of adults felt the US Treasury should continue making pennies A penny saved is... Those who always take pennies in change 18-29 46% 30-44 40% 45-64 56% 65-over Suppose we select a sample of 11 adults. a-1. How many of the 11 would we expect to indicate that the Treasury should continue making pennies? (Round your answer to 2 decimal places.) Expected adults a-2. What is the standard deviation? (Round your answer to 4 decimal places.) Standard deviation b. What is the likel hood that exactly 4 adults would indicate the Treasury should continue making pennies? (Round your answer to 4 decimal places.) Likelihood c. What is the likolhood at least 4 adults would indicate the Treasury should continue making pennies? (Round your answer to 4 decimal places.) Likelihood

Explanation / Answer

a-1)

As n = 11, p = 0.57,

u = mean = np =    6.27 [ANSWER]

*******************

A-2)
  
s = standard deviation = sqrt(np(1-p)) =    1.641980511 [ANSWER]

**********************

B)

Note that the probability of x successes out of n trials is          
          
P(n, x) = nCx p^x (1 - p)^(n - x)          
          
where          
          
n = number of trials =    11      
p = the probability of a success =    0.57      
x = the number of successes =    4      
          
Thus, the probability is          
          
P (    4   ) =    0.094687479 [ANSWER]

******************

D)

Note that P(at least x) = 1 - P(at most x - 1).          
          
Using a cumulative binomial distribution table or technology, matching          
          
n = number of trials =    11      
p = the probability of a success =    0.57      
x = our critical value of successes =    4      
          
Then the cumulative probability of P(at most x - 1) from a table/technology is          
          
P(at most   3   ) =    0.0461445
          
Thus, the probability of at least   4   successes is  
          
P(at least   4   ) =    0.9538555 [ANSWER]