At wind speeds above 1000 centimeters per second (cm/sec), significant sand-movi
ID: 3290889 • Letter: A
Question
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. Sixty-five wind speed readings gave an average velocity of x = 1075 cm/sec. Based on long-term experience, can be assumed to be 275 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.)
(b) Does the confidence interval indicate that the population mean wind speed is such that the sand is always moving at this site? Explain.
No. This interval indicates that the population mean wind speed is such that the sand may not always be moving at this site.
Yes. This interval indicates that the population mean wind speed is such that the sand may not always be moving at this site.
Yes. This interval indicates that the population mean wind speed is such that the sand is always moving at this site.
No. This interval indicates that the population mean wind speed is such that the sand is always moving at this site.
lower limit cm/sec upper limit cm/secExplanation / Answer
a) The statistical softwre output for this problem is:
One sample Z summary confidence interval:
: Mean of population
Standard deviation = 275
95% confidence interval results:
Hence,
95% confidence interval will be:
Lower limit = 1008 cm/sec
Upper limit = 1142 cm/sec
b) Option A is correct.
Mean n Sample Mean Std. Err. L. Limit U. Limit 65 1075 34.109552 1008.1465 1141.8535Related Questions
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