Jack is a college athlete who has been weighing himself weekly on the same scale in the athletic center for the past few years. Jack’s mean weight over the last nine weeks is 180 lbs. Over a period of a few months, Jack’s weight measurements are approximately normal, with a standard deviation of about 3 lbs. Assume that 3 lbs is the true standard deviation in Jack’s weight. Suppose that Jack asks you to compute a 90% confidence interval for his true mean weight. First, identify the positive critical value, , for a 90% level of confidence using software or a table of critical values. Then, derive the standard error of the mean, SE. Finally, compute the margin of error, , for the 90% confidence interval for Jack’s mean weight. Please enter all values to three decimal places.

step-by-step explanation:

and 90% of people marry there 7th grade love. since u have read this, u will be told good news 2night. if u don't pass this on nine comments ur worst week starts now this isn't fake. apparently if u copy and paste this on ten comments in the next ten minutes you will have the best day of ur life tomorrow. you will either get kissed or asked out in the next 53 minutes someone will say i love u

read more on -

large crystals result from very slow cooling.

evaporation of water: this would produce an evaporite which is a sedimentary rock. like a salt pan in a desert. not possible to have volcanic rocks originate this way.

crystalization in molten earth: slow cooling over time. (hundreds to millions of years)

crystalization at earth's surface: this results in fast cooling. (a few hours to a few months or years)

crystalization from cooling off hot water: that would be a hydrothermal deposit. while associated with volcanics they are not volcanic rocks themselves and usually occur fairly rapidly.