A research study measured the sounds generated during eating tortilla chips. Peak loudness was measured (in decibels at 20 cm away) for both open-mouth and closed-mouth chewing. A sample size of 10 chips was used for each trial. For open-mouth chewing the mean peak loudness was 60 decibels with a standard deviation of 15 decibels. For closed-mouth chewing the mean peak loudness was 53 decibels with a standard deviation of 16 decibels. Is there evidence that there is a difference (open-closed) in mean peak loudness for open and closed mouth chewing of tortilla chips? (

Simplify. 3(4+4x) (type your answer in with no spaces)

At wind speeds above 1000 centimeters per second (cm/sec), significant sand-moving events begin to occur. wind speeds below 1000 cm/sec deposit sand and wind speeds above 1000 cm/sec move sand to new locations. the cyclic nature of wind and moving sand determines the shape and location of large dunes. at a test site, the prevailing direction of the wind did not change noticeably. however, the velocity did change. fifty-nine wind speed readings gave an average velocity of x = 1075 cm/sec. based on long-term experience, σ can be assumed to be 245 cm/sec. (a) find a 95% confidence interval for the population mean wind speed at this site. (round your answers to the nearest whole number.) lower limit cm/sec upper limit cm/sec

Rachel is studying the population of a particular bird species in a national park. she observes every 10th bird of that species that she can find in the park. her conclusion is that the birds living in the park who belong to that species generally feed on insects. rachel's sample is . based on the sample she picked, rachel's generalization is