Answer:
Number of families that should be surveyed if one wants to be 90% sure of being able to estimate the true mean PSLT within 0.5 is at least 43.
Step-by-step explanation:
We are given that one wants to estimate the mean PSLT for the population of all families in New York City with gross incomes in the range $35.000 to $40.000.
If sigma equals 2.0, we have to find that how many families should be surveyed if one wants to be 90% sure of being able to estimate the true mean PSLT within 0.5.
Here, we will use the concept of Margin of error as the statement "true mean PSLT within 0.5" represents the margin of error we want.
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<u>SO, Margin of error formula is given by;</u>
Margin of error =
where,
= significance level = 10%
= standard deviation = 2.0
n = number of families
Now, in the z table the critical value of x at 5% (
) level of significance is 1.645.
SO, Margin of error =
0.5 =

n =
= 43.3 ≈ 43
Therefore, number of families that should be surveyed if one wants to be 90% sure of being able to estimate the true mean PSLT within 0.5 is at least 43.
Answer: ez
Step-by-step explanation:
its b
Answer:
-12
Step-by-step explanation:
Answer: (4,-4)
y=-4, x=4
Step-by-step explanation:
-4x=4y
4x-8y=12
-8y=-4x+12 Now I can substitute -4x for 4y
-8y=4y+12
-2y=y+12
-3y=12
y=-4
-4x=4y
-4x=4(-4)
x=4
Let’s put these into one fraction each:
Biking:
= (12*5)/8 miles
= 60/8 miles
This can be reduced to,
= 15/2 miles
Swimming:
= (5*2)/3 miles
= 10/3 miles
Running:
= (6*3)/8 miles
= 18/8 miles
This can be reduced to,
= 9/4
Now we add all the distances up:
= (15/2) + (10/3) + (9/4)
Now we just can add the numerators and the denominators. We must find the lowest common factor (LCF) for our 3 denominators (2,3,4). Our LCF turns out to be 12. *Remember what we do to the denominator we must do to the numerator. So:
= (15/2) + (10/3) + (9/4)
= [(15*6)/12] + [(10*4)/12] + [(9*3)/12]
= (90/12) + (40/12) + (27/12)
= (157/12)
Therefore Aaron Ran 157/12 miles or 13.08 miles.
Hope this helps!