A helicopter hovers over a mountain top, and a professional snowboarder drops onto the snow 252525 feet below. the snowboarder's
height off the ground, in feet, while falling can be modeled by a quadratic function of seconds of falling, ttt, which has the form h(t) = d - at^2h(t)=d−at 2 h, left parenthesis, t, right parenthesis, equals, d, minus, a, t, start superscript, 2, end superscript. if the snowboarder is still 212121 feet above the ground after falling for 0.50.50, point, 5 seconds, how long does the entire 252525 foot drop take? round your answer to the nearest hundredth of a second.
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Answer:
We need a sample size of at least 719
Step-by-step explanation:
We have that to find our level, that is the subtraction of 1 by the confidence interval divided by 2. So:
Now, we have to find z in the Ztable as such z has a pvalue of .
So it is z with a pvalue of , so
Now, find the margin of error M as such
In which is the standard deviation of the population and n is the size of the sample.
How large a sample size is required to vary population mean within 0.30 seat of the sample mean with 95% confidence interval?
This is at least n, in which n is found when . So
Rouding up
We need a sample size of at least 719