Answer:

Step-by-step explanation:
<u><em>the mean in period</em></u> 1 :
(2.3+2.1+2.2+2.2+2.2+2.1+2.4+2.5+2.2+2.0+1.9+1.9+2.1+2.2+2.3)÷15=21.733...
<u><em>the mean in period</em></u> 2 :
(2.3+2.1+3.3+1.5+3.6+1.6+3.0+1.1+4.7+2.1+2.4+1.9+2.8+0.5+2.3)÷15=23.466...
Since 23.466 > 21.733 then “The mean in period 2 is higher than the mean in period 1”.
1/5
1/3
8/100
Three fractions that are less than 40%.
Answer:
The answer is below
Step-by-step explanation:
a) For a normal model the sample size has to be equal or greater than 30 so that it can be a normal distribution.
b) Given that:
μ = 11.2 minutes, σ = 4.8 minutes, n = 45
The z score determines how many standard deviations the raw score is above or below the mean. It is given by:

For x < 10 minutes

Therefore from the normal distribution table, P(x < 10) = P(z < -1.68) = 0.0465
Answer:
186.3
To find the answer you have to do inverse operations
9×20.7=186.3
186.3÷20.7=9