-5(2x - 3) = 15 what is this
2 answers:
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Answer:
The arithmetic mean is 10.9
Step-by-step explanation:
In this question, we are tasked with calculating the arithmetic mean using the information given.
The arithmetic mean or otherwise called the average is the sum of all the values in a given set divided by the number of elements or count of the elements in that particular data set
Mathematically, the arithmetic mean can be found by dividing the sum of the data values by the number of data values.
In equation form, we have
Inserting the values, we have Arithmetic mean = 10998/1007 = 10.92 which is 10.9 to the nearest tenth
Answer:
The 80% confidence interval for the mean number of toys purchased each year is between 7.5 and 7.7 toys.
Step-by-step explanation:
We have that to find our level, that is the subtraction of 1 by the confidence interval divided by 2. So:
Now, we have to find z in the Ztable as such z has a pvalue of .
That is z with a pvalue of , so Z = 1.28.
Now, find the margin of error M as such
In which is the standard deviation of the population and n is the size of the sample.
The lower end of the interval is the sample mean subtracted by M. So it is 7.6 - 0.1 = 7.5
The upper end of the interval is the sample mean added to M. So it is 7.6 + 0.1 = 7.7
The 80% confidence interval for the mean number of toys purchased each year is between 7.5 and 7.7 toys.