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%.
Answer:
Step-by-step explanation:
12: 8,700
13: 42
14: 70,000
15: 5,000,000,000
16: 2,210
17: 34,100
18: 1,650
19: 149
20: 290,000
Answer: it is 65%
Step-by-step explanation:
The scatter plot has been attached
Answer:
Options C, D & E are true
Step-by-step explanation:
Option A is wrong because from the scatter plot, only four athletes were faster in the second race than in the first one.
Option B is wrong because only 1 athlete had his second race time differing from the first race time by exactly 2 seconds.
Option C is true because exactly 9 of the times for the first race were at least 16 seconds
Option D is true because there are exactly 3 athletes who had the same time in both races
Option E is true because 8 of the times for the second race were less than 17 seconds
Check the picture below.
make sure your calculator is in Degree mode.
