Add 7 to both sides
3x + 12 = 7x
Subtract 3x
12 = 4x
Divide by 4
x = 3
Answer:
The mean for the sampling distribution of the sample proportion is 0.29
The standard deviation for the sampling distribution of the sample proportion is 0.01435
Step-by-step explanation:
The mean for the sampling distribution of the sample proportion is always equal to the true population proportion, in this case; p = 0.29
The standard deviation for the sampling distribution of the sample proportion is calculated as;

Using the given values;
p = 0.29
1 - p = 0.71
n = 1000
The standard deviation becomes;

The s.d becomes 0.01435
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Yes! This would be accurate because she is, at random, selecting people to do the survey
Go up on the graph 9 times and then to the side 15 times.