Question

In: Statistics and Probability

Question 1 In a survey, 31 people were asked how much they spent on their child's...

Question 1

In a survey, 31 people were asked how much they spent on their child's last birthday gift. The results were roughly bell-shaped with a mean of $47 and standard deviation of $4. Construct a confidence interval at a 98% confidence level.
Give your answers as ¯x±ME to one decimal place.

_____ ± ____

Question 2

The table below contains the birth weights in grams of 26 African American babies born at BayState Medical Center in Springfield, Massachusetts in 1986. Compute a 95% confidence interval for birth weight.

Directions: Click on the Data button below to display the data. Copy the data into a statistical software package and click the Data button a second time to hide it.

Weight
2518
2758
2921
2927
2916
2933
2959
3045
3082
3286
3387
3419
3419
3777
3891
1102
1681
1929
2158
2191
2324
2358
2409
2391
2414
2478

Find the point estimate for the birth weights. Round your answer to 2 decimal places.
Determine the value of tctc. Round your answer to 5 decimal places.
Find the margin of error for the confidence interval. Round your answer to 1 decimal place.
Construct the confidence interval for birth weights. Enter your answer as an open interval of the form (a,b) and round to the nearest integer.
Babies weighing less than 2500 grams are considered to be of low birth weight. Can you conclude that the average birth weight is greater than 2500 grams?
- Yes, the entire confidence is above 25002500.
- No, the entire confidence interval is below 25002500.
- No conclusions can be drawn since the confidence interval contains 25002500.

Question 3

You want to obtain a sample to estimate a population mean. Based on previous evidence, you believe the population standard deviation is approximately σ=44.2. You would like to be 95% confident that your esimate is within 10.5 of the true population mean. How large of a sample size is required?

n= ______

Do not round mid-calculation. However, use a critical z value accurate to two (2) decimal places.

Expert Solution

1.

2.

No, the entire confidence interval is below 2500.

3.

orchestra answered 2 years ago

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