Five years ago, a county lottery official conducted a very extensive (and expensive) study to determine the average age of lottery players in the county. From the data, he estimated the true age to be about 50 years. Five years later, the lottery official wants to know if the average age is now different from 50 years. He plans to conduct a smaller (and less expensive) survey of lottery players. From a random sample of 81 players from the county, the average age is 48.7 years with a standard deviation of 8.5 years. (a) is there convincing evidence at the a = 0.05 significance level that the present-day average age of all lottery players in the county is different from 50 years.
(b) Referring to your conclusion in part fa), what type of error may have been made? Describe the error in the context of this study.

the figures below are made out of circles, semicircles, quarter … find the area and the perimeter of each figure and give your answers as a completely simplified exact value in terms of π (no approximations). remember that we'll also have to cut whatever areas we get in half, since we're only dealing

step-by-step explanation:

sine

step-by-step explanation:

b: |12 – x| ≤ 0.25

step-by-step explanation:      

let x be the possible lengths in inches, of the ribbons jaime cut.

we have been given that jaime is cutting strips of ribbon for a project. he tries to cut each piece to be 12 inches long, but sometimes he cuts it too long or too short by as much as 0.25 inch.  

we can represent this information in an inequality as:

by the definition of absolute value function we will get,

upon combining our inequalities we will get,

therefore, the inequality   describes all the possible lengths (x), in inches, of the ribbons jaime cut.

step-by-step explanation:

explanation:

infrared radiation has wavelength in the range between 700 nm and 1 mm. lets' convert these values into scientific notation, keeping in mind that:

let's start from the lower value, we have:

(we moved the dot two places to the left, so we increased the exponent by 2 units, from -9 to -7)

the higher value is:

so, the range of wavelength of infrared radiation is: