The minute hand of a clock is 4 inches long. how far does the tipof the minute hand move in 20 minnutes?
1 answer:
This is an arc length question, but it's a little hidden. The minute hand is the radius of the circle, so r=4. Next we need to know how much of the circle the tip of the minute hand will move through. Since there are 60 minutes in an hour, the minute hand will pass through 20/60=1/3 of the clock. Then we just use the circumference formula scaled by the amount of the clock we have:
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Answer:
The proportion of children that have an index of at least 110 is 0.0478.
Step-by-step explanation:
The given distribution has a mean of 90 and a standard deviation of 12.
Therefore mean, = 90 and standard deviation,
= 12.
It is given to find the proportion of children having an index of at least 110.
We can take the variable to be analysed to be x = 110.
Therefore we have to find p(x < 110), which is left tailed.
Using the formula for z which is p( Z < ) we get p(Z <
= 1.67).
So we have to find p(Z ≥ 1.67) = 1 - p(Z < 1.67)
Using the Z - table we can calculate p(Z < 1.67) = 0.9522.
Therefore p(Z ≥ 1.67) = 1 - 0.9522 = 0.0478
Therefore the proportion of children that have an index of at least 110 is 0.0478