It is 639.5. this is how you round numbers to the nearest tenth:
if the digit in the hundredths place is 5 or more you round up one, if it is lower than 5 it stays the same, pay no attention to the thousandths place....ex--> 0.497
the 4 is the tenths place
th 9 is the hundredths place
the 7 is the thousandths place......since 9 is 5 or more you round the 4 up one number, so the 4 would be a 5. pay no attention to the 7. lets do another
0.426
the 4 stays as a 4 because 2 is a lower number than 5.
Answer:
point? this question could have many answers
Answer:
The standard deviation is used in conjunction with the mean to numerically describe distributions that are bell shaped. The mean measures the center of the distribution, while the standard deviation measures the spread of the distribution.
Step-by-step explanation:
Problems of normally distributed samples can be solved using the z-score formula.
In a set with mean
and standard deviation
, the zscore of a measure X is given by

The mean is the average value of the measures while the standard deviation measures how spread the measures are from the mean. So
The standard deviation is used in conjunction with the mean to numerically describe distributions that are bell shaped. The mean measures the center of the distribution, while the standard deviation measures the spread of the distribution.
Answer:
70 students
Step-by-step explanation:
As, 30% Mike surveyed
And these 30% are 21 students
So 30% of X = 21
= 30/100 x X = 21
= 30X = 2100
So X = 2100/30
X = 70
So 70 students were surveyed