Review of Hypothesis Testing and Confidence Intervals

35 randomly selected boys and 42 randomly selected girls at Harrison High School were asked: "How many times a day do you charge your cell phone?" After obtaining the appropriate summary statistics from the sample, what would be the appropriate significance test to determine if HHS boys charge their cell phones more frequently than HHS girls?

• 2-proportion Z-Test

• 2-mean T-Test

• Matched pairs T-test

• 1-mean T-Test

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CCSS.HSS.ID.A.4

What is the appropriate critical value to use for your margin of error if you are constructing a 99% confidence interval for 2 proportions?

(a)  

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CCSS.HSS.IC.B.4

When conducting a hypothesis test and your p-value is greater than your significance level, what is the appropriate conclusion to make?

• Reject Ha

• Accept Ho

• Reject Ho

• Fail to Reject Ho

38 out of 60 randomly selected NJ residents are Yankees fans. 41 out of 70 randomly selected NY residents are Yankees fans. The corresponding 95% confidence interval is (-.1203, .2155). Does this interval indicate that a larger proportion of NJ residents are fans of the Yankees than NY residents?

• Yes, because the positive bound is larger than the negative bound.

• No, because the interval contains both positive and negative values indicating it could go either way.

• No, because the values are less than 95%.

• Yes, because 38/60 (.633) is bigger than 41/70 (.586).

Tags

CCSS.HSS.IC.B.4

A random sample of 85 people were selected and had their heart rate measured. If we were to construct a confidence interval or conduct a hypothesis test, how many degrees of freedom would we need?

(a)  

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CCSS.HSS.IC.B.4

75 randomly selected people were asked to run a lap around the track on Monday with Nike sneakers on and have their time recorded. The same 75 people were asked to run a lap around the track on Tuesday with Adidas sneakers on and have their time recorded. Which would be the appropriate significance test to determine whether or not people Nike sneakers are faster than Adidas sneakers?

• 2-Proportion Z-test

• 2-mean T-Test

• Matched Pairs T-Test

• 1 mean T-Test

62 randomly selected people at Shop Rite and 57 randomly selected people at Stop and Shop were asked how much money their grocery bill was. The mean and standard deviation from the sample at Shop Rite was $167 and $49, while the mean and standard deviation at Stop and Shop was $205 and $39. What would be the p-value associated with a hypothesis test to determine if people at Stop and Shop spend more money on average than people at Shop Rite? Give your answer as a decimal with 3 significant figures.

(a)  

54 newly hired employees were randomly selected at a major company and asked what the balance was in their savings account. The sample produced a mean of $2,519 with a standard deviation of $942. If we wanted to test the hypothesis that savings account balances for newly hired employees as this company were less than $3,000, what would be the value of the test statistic after conducting the appropriate hypothesis test? Give the appropriate variable of the test statistic and the value rounded to two decimal places.

(a)  

47 students from Lyndhurst HS and 62 students from Rutherford HS were asked how many times a year they go to American Dream mall. The mean and standard deviation for Lyndhurst was 9.27 and 4.8, while the mean and standard deviation for Rutherford was 12.55 and 6.2. Does this provide convincing evidence at the .01 level that Rutherford HS students go to American Dream mall at least 2 more times a year than Lyndhurst HS students? Show ALL of your work in the box and give the FULL explanation!

Tags

CCSS.HSS.ID.A.4

109 randomly selected college students were asked, "Did you select your college because it had a reputation as a 'party school' ?" From those 109, 45 responded yes. At the .05 significance level, what is the correct conclusion after conducting the appropriate hypothesis test to determine if less than half of college students chose their college because it had a reputation as a 'party school'?

• P-value is greater than .05, reject Ho and conclude that less than half of students chose their school because it was a party school.

• P-value is greater than .05, reject Ha and conclude that more than half of students chose their school because it was a party school.

• P-value is less than .05, reject Ho and conclude that less than half of students chose their school because it was a party school.

• P-value is greater than .05, fail to reject Ho and conclude that we do not know if less than half of students chose their school because it was a party school.

Tags

CCSS.HSS.IC.B.4