So in example you need to round 73.2754 to the nearest whole number. Since the number in the tenths column is less than 5 the number is rounded down to 73.
<span>In a normal distribution 68.27% of the values are within one standard deviation from the mean, 95.5% of the values are within two standard deviations from the mean, and 99.7 % of the values are within three standard deviations of the mean
With that you have the answer to the three questions:
</span>
<span>a. significantly high (or at least 2 standard deviations above the mean).
99.5% of the values are within 2 standard deviations from the mean, half of 100% - 95.5% = 4.5% / 2 = 2.25% are above the mean, so the answer is 2.25%
b. significantly low (or at least 2 standard deviations below the mean).
The other half are below 2 standard deviations, so the answer is 2.25%
c. not significant (or less than 2 standard deviations away from the mean).
As said, 95.5% are within the band of two standard deviations from the mean, so the answer is 95.5%.
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114 years (this has to be 20 characters so ignore this)
The population triples ( P × 3 ) every ten minutes...
So if ten minutes is reached there will be 1,200 bacteria.
Edited - missed the question
** The units for time should be in minutes.
P = 400 × 3^(t/10)
at t = 0 ; P = 400
at t = 10 ; P = 1,200
When P = 600
600 = 400 × 3^(t/10)
6/4 = 3^(t/10)
Log(3/2) = Log(3^(t/10))
power rule
Log(3/2) = (t/10) Log(3)
10 × Log(3/2)/Log(3) = t
3.69 minutes the population will be at 600 bacteria
Unites for time are in minutes.
