First, I'd like to say that this question is flawed because the diameter of the spool changes as you pull the line out. Some would argue it's negligible I suppose.
At any rate, assuming there's a magic spool where the diameter doesn't change, let's find the cicumference so we can find the length of one wrap around the spool.
circumference = 2*pi*r = 2 * pi * 4cm = about 25.133 cm
Now if it turns 16 times we'll have 16 times the circumference.
16 * (25.133 cm)
= 402.128 cm
Answer:
D would be your answer
Step-by-step explanation:
Answer:A=8-1/57=455/57=7.98
Step-by-step explanation:
Answer:
The percentage of students who scored below 620 is 93.32%.
Step-by-step explanation:
Problems of normally distributed samples are solved using the z-score formula.
In a set with mean
and standard deviation
, the zscore of a measure X is given by:

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.
In this question, we have that:

Percentage of students who scored below 620:
This is the pvalue of Z when X = 620. So



has a pvalue of 0.9332
The percentage of students who scored below 620 is 93.32%.