We have to define an interval about the mean that contains 75% of the values. This means half of the values will lie above the mean and half of the values lie below the mean.
So, 37.5% of the values will lie above the mean and 37.5% of the values lie below the mean.
In a Z-table, mean is located at the center of the data. So the position of the mean is at 50% of the data. So the position of point 37.5% above the mean will be located at 50 + 37.5 = 87.5% of the overall data
Similarly position of the point 37.5% below the mean will be located at
50 - 37.5% = 12.5% of the overall data
From the z table, we can find the z value for both these points. 12.5% converted to z score is -1.15 and 87.5% converted to z score is 1.15.
Using these z scores, we can find the values which contain 75% of the values about the mean.
z score of -1.15 means 1.15 standard deviations below the mean. So this value comes out to be:
150 - 1.15(25) = 121.25
z score of 1.15 means 1.15 standard deviations above the mean. So this value comes out to be:
150 + 1.15(25) = 178.75
So, the interval from 121.25 to 178.75 contains the 75% of the data values.
Answer:
<em>The probability of obtaining a score less than 60 is 2.28%
</em>
<em>It happens 2 out of 100 times.</em>
Step-by-step explanation:
If the mean μ = 80 and the standard deviation σ = 10, then we need to find the probability that an X value is less than 60.
Then we find
To find this probability we use the Z statistic.
This is the same as
We look for this value in the table for the normal distribution of right queue and we have:
<em>The probability of obtaining a score less than 60 is 2.28%
</em>
<em>It happens 2 out of 100 times.</em>
Answer: False
The tenth place means there will be 1 decimal.
75.2515
because they 5 is left to the 2, and 5 means we round up, the 2 becomes a 3. Therefore, it would equal 75.3
Answer:
Step-by-step explanation:
Answer:
(c) 4x - 7
Step-by-step explanation:
7x - 3x
= -4x
-5 -2
= -7
4x - 7
