Answer:
Elizabeth spent 17.5 hours and her sister spent 12.5 hours.
Step-by-step explanation:
Let x be the number of hours that Elizabeth shoveled and y be the number of hours that her sister shoveled.
Number of hours they shoveled = 30
So, x + y = 30 or
y = 30 - x
Jenna charged $12 per sidewalk.
So, her total earnings = 12x
Her sister charged $11 per sidewalk.
So, her total earnings = 11y.
Their total income = $347.50.
So, 12x + 11y = 347.5
Substitute y = 30 - x,
12x + 11(30 - x) = 347.5
12x + 330 - 11x = 347.5
x + 330 = 347.5
x = 347.5 - 330
x = 17.5 and
y = 30 - x = 30 - 17.5 = 12.5.
Hence, Elizabeth spent 17.5 hours and her sister spent 12.5 hours.
Answer:

Step-by-step explanation:













Answer:
standard error = 1.63
Step-by-step explanation:
To calculate the standard error we need to know the standard deviation (σ) and the sample size (n) (see the attached formula).
To obtain the standard deviation we use the given sample variance of 77.4 years:
σ²= variance
Therefore:
σ = √77.4 = 8.8
Now we can calcuate the estimated standard error:
standard error = σ /√n = 8.8/√29 = 1.63
The standard error gives us an estimation about how far the mean of the sample is from the mean of the entire population, and in this case is 1.63.
It’s D, because when using the word “area” it means you have to multiply. The term “times” in this case ALSO means to multiply. The iPadPro is 1.5 TIMES the size of the iPad mini. Hopefully this is correct good luck
XII should be your answer.