Answer:
Step-by-step explanation:
First, write an equation. 55x+40=190.
X represents the hours the electrician works. The 55 represents the $55 that she charges for each hour she works. The +40 for the $40 that was the price just to come to your house. The 190 is the total cost. Now, solve that equation.
55x+40=190
55x=150
x=2.72727272...
So the answer is 2.727 hours. It can be rounded as needed or turned into a decimal, 2 8/11.
Answer:
Step-by-step explanation:
Average Temperatures Suppose the temperature (degrees F) in a river at a point x meters downstream from a factory that is discharging hot water into the river is given by
T(x) = 160-0.05x^2
a. [0, 10]
For x = 0
T(0) = 160 - 0.05 × 0^2
T(0) = 160
For x = 10
T(10) = 160 - 0.05 × 10^2
T(10) = 160 - 5 = 155
The average temperature
= (160 + 155)/2 = 157.5
b. [10, 40]
For x = 10
T(10) = 160 - 0.05 × 10^2
T(10) = 160 - 5 = 155
For x = 40
T(10) = 160 - 0.05 × 40^2
T(10) = 160 - 80 = 80
The average temperature
= (80 + 155)/2 = 117.5
c. [0, 40]
For x = 0
T(0) = 160 - 0.05 × 0^2
T(0) = 160
For x = 40
T(10) = 160 - 0.05 × 40^2
T(10) = 160 - 80 = 80
The average temperature
= (160 + 80)/2 = 120
Answer:
She pays $2.5 per pound
Step-by-step explanation:
Answer:
d. None of the above.
Step-by-step explanation:
<em>a. By the law of large numbers, it would again be 46%.
</em>
FALSE. This proportion (46%) is a sample statistic, that can or can not be repeated in another sample.
<em>b. By the law of large numbers, the smaller (second) survey will certainly produce a sample proportion farther from the true population proportion than the larger (first) survey.
</em>
FALSE. Smaller samples will produce wider confidence intervals for the estimation of the population proportion, but larger samples does not necessarily gives us better point estimations of the true proportion. A small sample can be closer to the true proportion than a large sample, although is less probable.
<em>c. The proportion computed from the sample of 5000 people would be more accurate because smaller samples tend to be more homogeneous than larger samples.
</em>
FALSE. There is no evidence to claim that smaller samples are more homogeneous.
<em>d. None of the above.</em> TRUE
