NAME: ______Worksheet 10.2 B
Complete each problem. Don’t forget to check conditions for confidence intervals and tests of significance. Write all sentences/conclusions, and include units.
1-Here are the IQ test scores for and SRS of 33 seventh-grade girls in a Midwest School District.
1141001048910291114114103105109
1081301201321111281181198672100
11110374112107103989611211293
a)Enter the data into your calculator in L1, and then run 1-Var Stats. Record the sample mean (), the sample standard deviation (Sx), and the sample size (n). Use this info for this problem.
b)Check the conditions
c)Create a 98% confidence interval for the average IQ score for seventh-grade girls.
d)The average IQ score for any age group is supposed to be 100. Use the information in this problem to test and see if the average IQ score is different from 100. Use α=0.03.
2- Complete #54 on page 514-515 in the textbook.
3- An environmental group collects a liter of water from an SRS of 45 locations along a stream and measures the amount of contamination in each specimen. The average of the sample is 4.62 milligrams and the standard deviation is 0.92 milligrams.
a)Check the conditions
b)Create a 95% confidence interval for the average amount of contamination in the stream
c)It has been claimed that the contamination level in the stream is 5 milligrams. Using the info in this problem, test to see if stream’s contamination level has decreased.
4- I have a 94% confidence interval that is (45.6, 59.3).
a)Suggest a possible 98% confidence interval
b)Suggest a possible 91% confidence interval
5- I have a 95% confidence interval that is (32.9, 48.4)
a)What is the sample mean?
b)What is the margin of error?
c)If I increase my confidence to 99%, what will happen to my margin of error and to my confidence interval?
d)If I increase my sample size, what will happen to my margin of error and to my confidence interval?
6- Complete #57 on page 515 in the textbook. Check conditions & then perform a full test of significance.
7- Complete #46 on page 509 in the textbook. Check conditions (you can assume that the population is normally distributed, so the sample size being less than 30 is ok) & then create and interpret a 95% confidence interval.
EXTRA:
8-A recent study claims that out of all the ice cream flavors, 52% of people say chocolate is their favorite flavor. You think this is too high! You take a random sample of 115 customers at a local ice cream store and find that only 51 of them say that chocolate is their favorite. Check the conditionsthen test the claim at a significance level of 0.05.
9- A company is marketing its new toy for children ages 3-8, however they are interested in the proportion of 4 to 5-year-old children like the toy. They take a SRS of 53 4 to 5-year-old children and perform a series of tests to determine whether the child likes the toy or not. They determine that of the children in their sample, 28 like their toy. Check the conditionsthen estimate the percent of children that like the toy using a 96% level of confidence. Interpret your interval.
NAME: ______Worksheet 10.2 B
Complete each problem. Don’t forget to check conditions for confidence intervals and tests of significance. Write all sentences/conclusions, and include units.
1- Here are the IQ test scores for and SRS of 33 seventh-grade girls in a Midwest School District.
1141001048910291114114103105109
1081301201321111281181198672100
11110374112107103989611211293
a)Enter the data into your calculator in L1, and then run 1-Var Stats. Record the sample mean (), the sample standard deviation (Sx), and the sample size (n). Use this info for this problem.
b)Check the conditions
c)Create a 98% confidence interval for the average IQ score for seventh-grade girls.
d)The average IQ score for any age group is supposed to be 100. Use the information in this problem to test and see if the average IQ score is different from 100. Use α=0.03.
2- Complete #54 on page 514-515 in the textbook.
3- An environmental group collects a liter of water from an SRS of 45 locations along a stream and measures the amount of contamination in each specimen. The average of the sample is 4.62 milligrams and the standard deviation is 0.92 milligrams.
a)Check the conditions
b)Create a 95% confidence interval for the average amount of contamination in the stream
c)It has been claimed that the contamination level in the stream is 5 milligrams. Using the info in this problem, test to see if stream’s contamination level has decreased.
4- I have a 94% confidence interval that is (45.6, 59.3).
a)Suggest a possible 98% confidence interval
b)Suggest a possible 91% confidence interval
5- I have a 95% confidence interval that is (32.9, 48.4)
a)What is the sample mean?
b)What is the margin of error?
c)If I increase my confidence to 99%, what will happen to my margin of error and to my confidence interval?
d)If I increase my sample size, what will happen to my margin of error and to my confidence interval?
6- Complete #57 on page 515 in the textbook. Check conditions & then perform a full test of significance.
7- Complete #46 on page 509 in the textbook. Check conditions (you can assume that the population is normally distributed, so the sample size being less than 30 is ok) & then create and interpret a 95% confidence interval.
EXTRA:
8-A recent study claims that out of all the ice cream flavors, 52% of people say chocolate is their favorite flavor. You think this is too high! You take a random sample of 115 customers at a local ice cream store and find that only 51 of them say that chocolate is their favorite. Check the conditions & then test the claim at a significance level of 0.05.
9- A company is marketing its new toy for children ages 3-8, however they are interested in the proportion of 4 to 5-year-old children like the toy. They take a SRS of 53 4 to 5-year-old children and perform a series of tests to determine whether the child likes the toy or not. They determine that of the children in their sample, 28 like their toy. Check the conditions & then estimate the percent of children that like the toy using a 96% level of confidence. Interpret your interval.