Plz help me with questions 9,10,11. Plzz
1 answer:
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Answer:
1.) .399
2.) {.369, .429}
Step-by-step explanation:
The proportion of criminals in this sample that were caught was =.39944, .399 rounded to three decimal places.
To construct the confidence interval, you need three pieces of information: the statistic, the critical value, and the standard error.
The statistic is given in the first part of the problem with the proportion of criminals in the sample that were caught was .399.
The critical value, we are told, is the z equivalent of 90%, or 1.645. You can find this value using a z table or with the inverse normal function on a calculator.
Finally, we need the standard error. The formula for standard error for a proportion with a single population is so in this situation it would be
=.0183.
The confidence interval would be .399±.018×1.645 or .399±.030 {.369, .429}
Answer:
Small gift: $2
Large gift: $7
Step-by-step explanation:
Let x represent cost of wrapping each small gift and y represent cost of wrapping each large gift.
We have been given that day one 41 small gifts were wrapped and 45 large were wrapped equaling $397.
We can represent this information in an equation as:
We are also told that day two 30 small gifts were wrapped and 47 large were wrapped equaling $389. We can represent this information in an equation as:
From equation (1), we will get:
Upon substituting this value in equation (2), we will get:
Therefore, cost to wrap a large gift is $7.
Upon substituting in equation
, we will get:
Therefore, cost to wrap a small gift is $2.