Mathematics, 22.09.2019 22:30 Yasido888
The mean preparation fee h& r block charged retail customers last year was $183 (the wall street journal, march 7, 2012). use this price as the population mean and assume the population standard deviation of preparation fees is $50.
a. what is the probability that the mean price for a sample of 30 h& r block retail customers is within $8 of the population mean?
b. what is the probability that the mean price for a sample of 50 h& r block retail customers is within $8 of the population mean?
c. what is the probability that the mean price for a sample of 100
Answers: 1
and the population standard deviation, 
![P(183-8\leq\bar{x}\leq183+8)=P(175\leq\bar{x}\leq191) \\ \\ =P(\bbar{x}\leq191)-P(\bbar{x}\leq175)=P\left(z\leq \frac{191-183}{ \frac{50}{ \sqrt{30} } } \right)-P\left(z\leq \frac{175-183}{ \frac{50}{ \sqrt{30} } } \right) \\ \\ =P(z\leq0.8764)-P(z\leq-0.8764) \\ \\ =P(z\leq0.8764)-[1-P(z\leq0.8764)] \\ \\ =2P(z\leq0.8764)-1=2(0.80958)-1 \\ \\ =1.61916-1=0.61916\approx62\%](/tpl/images/0253/2227/644db.png)
![P(183-8\leq\bar{x}\leq183+8)=P(175\leq\bar{x}\leq191) \\ \\ =P(\bbar{x}\leq191)-P(\bbar{x}\leq175)=P\left(z\leq \frac{191-183}{ \frac{50}{ \sqrt{50} } } \right)-P\left(z\leq \frac{175-183}{ \frac{50}{ \sqrt{50} } } \right) \\ \\ =P(z\leq1.131)-P(z\leq-1.131) \\ \\ =P(z\leq1.131)-[1-P(z\leq1.131)] \\ \\ =2P(z\leq1.131)-1=2(0.87105)-1 \\ \\ =1.7421-1=0.7421\approx74\%](/tpl/images/0253/2227/b8683.png)
![P(183-8\leq\bar{x}\leq183+8)=P(175\leq\bar{x}\leq191) \\ \\ =P(\bbar{x}\leq191)-P(\bbar{x}\leq175)=P\left(z\leq \frac{191-183}{ \frac{50}{ \sqrt{100} } } \right)-P\left(z\leq \frac{175-183}{ \frac{50}{ \sqrt{100} } } \right) \\ \\ =P(z\leq1.6)-P(z\leq-1.6) \\ \\ =P(z\leq1.6)-[1-P(z\leq1.6)] \\ \\ =2P(z\leq1.6)-1=2(0.9452)-1 \\ \\ =1.8904-1=0.8904\approx89\%](/tpl/images/0253/2227/b4bab.png)
Another question on Mathematics
Mathematics, 21.06.2019 17:30
The sales totals at macy's food store have increased exponentially over the months. which of these best shows the sales in the first three months?
Answers: 2
Mathematics, 21.06.2019 23:30
Which of the following exponential functions goes through the points (1, 6) and (2, 12)? f(x) = 3(2)x f(x) = 2(3)x f(x) = 3(2)−x f(x) = 2(3)−x
Answers: 1
Mathematics, 21.06.2019 23:30
The approximate line of best fit for the given data points, y = −2x − 2, is shown on the graph.which is the residual value when x = –2? a)–2 b)–1 c)1 d)2
Answers: 2
You know the right answer?
The mean preparation fee h& r block charged retail customers last year was $183 (the wall street...
Questions
History, 06.07.2019 19:00
Physics, 06.07.2019 19:00
Mathematics, 06.07.2019 19:00
Mathematics, 06.07.2019 19:00
History, 06.07.2019 19:00
Mathematics, 06.07.2019 19:00
Mathematics, 06.07.2019 19:00
Chemistry, 06.07.2019 19:00
History, 06.07.2019 19:00
Mathematics, 06.07.2019 19:00
Mathematics, 06.07.2019 19:00
History, 06.07.2019 19:00
Mathematics, 06.07.2019 19:00
