1.Supposezis the standard normal variable. Draw the normal curve for each of the following probability statements to visualize the required area. Report answers accurate to at least 4 decimal places.

a)P(z<-1.13givenz<0)=

b)P(z-0.66orz>1.21)=

2.Supposez is the standard normal variable. Draw the normal curve for each of the following probability statements to visualize the required area and determine the missing values.Report answers accurate to 2 decimal places.

a)P(z orz>2.67)=0.8116

3.A population of values has a normal distribution with=219.6

and=8.5. You intend to draw a random sample of sizen=14. First calculatez, round it to two (2) decimal places, then use the roundedz

-score to determine the required probability accurate to four (4) decimal places.

a)Find the probability that a single randomly selected value is less than 223.9.

P(x<223.9)=

4.The number of trades (in thousands) completed daily by an online stock brokerage follows a normal distribution with a mean of 107.4 and a standard deviation of 24.6. On average, the brokerage receives $8.4 commission per trade.

For samples of sizen=18days:

a)For the given sample size, what is the minimum average daily commissions receivable from the highest 20% volume trading days?

Round to the nearest thousand dollars.

5.You measure 22 textbooks' weights, and find they have a mean weight of 43 ounces. Assume the population is normally distributed with a standard deviation of 10.7 ounces. Based on this, construct a 90% confidence interval for the true population mean textbook weight.

Give your answers correct to at least two decimal places.

Lower Limit =

Upper Limit =

6.

You measure 40 turtles' weights, and find they have a mean weight of 62 ounces. Assume thepopulation standard deviationis 14.5 ounces. Based on this, construct a 90% confidence interval for the true population mean turtle weight.

Give your answers asxME, to two decimal places

------------ounces

7.Ifn=13,x=37, ands=9

, construct a confidence interval at a90%

confidence level. Assume the data came from a normally distributed population.

Give your answers to one decimal place.

----- << ------

8.You want to obtain a sample to estimate a population mean. Based on previous evidence, you believe the population standard deviation is approximately =49.4. You would like to be 92% confident that your esimate is within 0.2 of the true population mean. How large of a sample size is required?

Do not round mid-calculation. However, use acritical z value accurate to two (2) decimal places.

n=

9.A study is conducted to estimate the mean completion time of a task to within 2 minutes 24 seconds of the population mean. Suppose completion time is normally distributed with a standard deviation of 9 minutes 42 seconds. What minimum sample size is required at the 89.9% confidence level?

You must use a criticalzvalue rounded to two (2) decimal places.

Do not round other intermediate results. Report final answer as an integer.

Minimum sample size required=