The national average on a certification exam in the US last year was 68.

The national average on a certification exam in the US last year was 68. For a sample of participants (n=64) who participated in a preparatory program before the exam, the mean was 76 with a sample standard deviation of 4. Using alpha = .05, is there a statistically significant difference between the study participants’ mean and the national average?

Expert Solution

Below are the null and alternative Hypothesis,
Null Hypothesis, H0: μ = 68
Alternative Hypothesis, Ha: μ ≠ 68

Rejection Region
This is two tailed test, for α = 0.05 and df = 63
Critical value of t are -1.998 and 1.998.
Hence reject H0 if t < -1.998 or t > 1.998

Test statistic,
t = (xbar - mu)/(s/sqrt(n))
t = (76 - 68)/(4/sqrt(64))
t = 16

P-value Approach
P-value = 0
As P-value < 0.05, reject the null hypothesis.

orchestra answered 2 years ago

the national average for verbal section of the graduate record exam

Over the last several years, the average exam grade in social psychology was 86, with a...

Over the last several years, the average exam grade in social psychology was 86, with a standard deviation of 7. This year, 25 social psychology students have a mean of 82. Are these students different from average social psychology students? m = s = M = N = One-tailed or two-tailed? Critical value (with  = .05): Null Hypothesis (H0): This sample________________________________________________________ ___________________________________________________________________________________ Alternative Hypothesis (Ha): This sample ___________________________________________________ ___________________________________________________________________________________ Compute z: z = Reject or fail...

After graduation you plan to sit for the certification exam. How will you prepare for the...

After graduation you plan to sit for the certification exam. How will you prepare for the final test to ensure a positive outcome and earn your CMA/RMA credential?

The size of the raccoon population at a national park last year was 180.

The size of the raccoon population at a national park last year was 180. This year, the population is 189. If the population increases exponentially, find the population of raccoons in 4 years. Use P = P0ekt where P0 represent the initial population. Round to the nearest whole number.

Scenario: Melissa Denton is a 68-year old individual who retired from Vanguard Corporation last year. Vanguard...

Scenario: Melissa Denton is a 68-year old individual who retired from Vanguard Corporation last year. Vanguard is a multi-national corporation employing over 10,000 employees. She worked for the company for over 20 years, and was fully insured for purposes of Social Security retirement benefits, which she began receiving at age 63. At age 65, her Medicare Part A coverage began, and she opted to receive Medicare Part B coverage. Melissa has come to you with the following questions regarding her...

US economy has experienced a significant rise in its national debt over the last 30 years?...

US economy has experienced a significant rise in its national debt over the last 30 years? What do you think the reasons for such change have been? What would you suggest for its remedy in the next decade? Explain your suggestions from the perspective of their economic impact.

Generate a graph of the last 20 years of the national debt and of the national...

Generate a graph of the last 20 years of the national debt and of the national debt as a percentage of GDP on a separate graph. Explain what has happened to both over time.

Over the last year the inflation rate was 3.8 percent and the interest rate on US...

Over the last year the inflation rate was 3.8 percent and the interest rate on US Treasury Bonds was slightly below 2 percent. As an investor in bonds a. what would you expect to happen to interest rates? b. using the three bond rules, in terms of prices, maturity, and coupon rates, what type of bonds should an investor purchase? Explain. c. Which bond is more price sensitive, a zero coupon 20 year to maturity government issued bond or a...

The Office for National Statistics (ONS) in the UK last year proposed a new price index-a...

The Office for National Statistics (ONS) in the UK last year proposed a new price index-a CPI that includes housing costs-called the CPIH. The rationale given for this proposal is that "the biggest cost for most homeowners is the cost of repaying their mortgage. But mortgage interest payments are not included in the CPI, nor are a variety of other costs, such as house depreciation, buildings insurance and ground rent, and house transaction costs such as estate agents' fees, survey...

As you showed on the last exam, an experiment at U of Arkansas a couple of...

As you showed on the last exam, an experiment at U of Arkansas a couple of years ago showed that the genes for CHF and RA are linked by a distance of 10.2 cM in pigs. In order to test the linkage relationship obtained by the U of Arkansas team, a U of Missouri biology team repeated the experiment making exactly the same cross, but using independently obtained pigs. Healthy pigs: 255 CHF: 40 RA: 44 Both CHF & RA:...

Question