Step-by-step explanation:
Ben and Joel are raising money for their class trip by selling wrapping paper. Ben raised $43.50 by selling 12 rolls of solid pa
1 answer:
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Answer:
Step-by-step explanation:
When we factor expressions, we look for factors within the terms that are alike, or in other words, we look for common factors. Here, and
only have one common factor:
. Therefore, to factorize this expression, divide both terms by
.
Now, we've "carried" out of the expression and have therefore factored it.
I hope this helps!
Answer:
we cannot conclude hat the proportion of wives married less than two years who planned to have children is significantly higher than the proportion of wives married five years
Step-by-step explanation:
Given that in a study on the fertility of married women conducted by Martin O’Connell and Carolyn C. Rogers for the Census Bureau in 1979, two groups of childless wives aged 25 to 29 were selected at random, and each was asked if she eventually planned to have a child. One group was selected from among wives married less than two years and the other from among wives married five years.
Let X be the group married less than 2 years and Y less than 5 years
X Y Total
Sample size 300 300 600
Favouring 240 288 528
p 0.8 0.96 0.88
p difference = -0.16
Std error for difference =
Test statistic = p difference/std error=-6.03
p value <0.000001
Since p is less than alpha 0.05 we cannot conclude hat the proportion of wives married less than two years who planned to have children is significantly higher than the proportion of wives married five years
Answer:
a) p-hat (sampling distribution of sample proportions)
b) Symmetric
c) σ=0.058
d) Standard error
e) If we increase the sample size from 40 to 90 students, the standard error becomes two thirds of the previous standard error (se=0.667).
Step-by-step explanation:
a) This distribution is called the <em>sampling distribution of sample proportions</em> <em>(p-hat)</em>.
b) The shape of this distribution is expected to somewhat normal, symmetrical and centered around 16%.
This happens because the expected sample proportion is 0.16. Some samples will have a proportion over 0.16 and others below, but the most of them will be around the population mean. In other words, the sample proportions is a non-biased estimator of the population proportion.
c) The variability of this distribution, represented by the standard error, is:
d) The formal name is Standard error.
e) If we divided the variability of the distribution with sample size n=90 to the variability of the distribution with sample size n=40, we have:
If we increase the sample size from 40 to 90 students, the standard error becomes two thirds of the previous standard error (se=0.667).