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Smartphone Shopping According to a USA Today snapshot, a large proportion of American shoppers own smartphones and use them while shopping to take pictures of items \((51 \%),\) to search for coupons \((49 \%)\) or to compare prices among retailers \((43 \%) .^{13}\) Suppose that a random sample of 50 American shoppers is selected and \(x\) is the number who use their phones to search for coupons. Assume that the \(49 \%\) figure is correct. a. What is the average number of shoppers who use their smartphones to search for coupons? b. What is the standard deviation of \(x\) ? c. If you were to observe a value of \(x\) less than or equal to \(15,\) would you consider this to be an unusual occurrence? Explain.

Finding z-Values Let \(z\) be a standard normal random variable with mean \(\mu=0\) and standard deviation \(\sigma=1 .\) Find the value \(c\) that satisfies the inequalities given in Exercises 29-35. $$ P(z>c)=.025 $$

Let \(z\) be a standard normal random variable with mean \(\mu=0\) and standard deviation \(\sigma=1 .\) Find the value \(c\) that satisfies the inequalities given. $$ P(z

Let \(z\) be a standard normal random variable with mean \(\mu=0\) and standard deviation \(\sigma=1 .\) Find the value \(c\) that satisfies the inequalities given. $$ P(-c

Let \(z\) be a standard normal random variable with mean \(\mu=0\) and standard deviation \(\sigma=1 .\) Find the value \(c\) that satisfies the inequalities given. The area to the left of \(c\) is \(.9505 .\)

Let \(z\) be a standard normal random variable with mean \(\mu=0\) and standard deviation \(\sigma=1 .\) Find the value \(c\) that satisfies the inequalities given. The area to the left of \(c\) is \(.05 .\)

Let \(z\) be a standard normal random variable with mean \(\mu=0\) and standard deviation \(\sigma=1 .\) Find the value \(c\) that satisfies the inequalities given. $$ P(-c

Let \(z\) be a standard normal random variable with mean \(\mu=0\) and standard deviation \(\sigma=1 .\) Find the value \(c\) that satisfies the inequalities given. $$ P(-c

Answer the questions in Exercises \(36-43\) for a normal random variable \(x\) with mean \(\mu\) and standard deviation \(\sigma\) specified in the exercises. \(\mu=10\) and \(\sigma=2\). Find the probability that \(x\) is greater than 13.5 .

For a normal random variable \(x\) with mean \(\mu\) and standard deviation \(\sigma\) specified in the exercises. \(\mu=10\) and \(\sigma=2\). Find the probability that \(x\) is less than 8.2 .