The Statistical Abstract of the United States (109th edition) reported that the mean age of all U. S. registered merchant vessels is 23.6 years. Records for 38 randomly selected U. S. registered grain cargo ships showed that the mean age was 26.7 years with a standard deviation of 5.2 years. Is this type of ship older than the national average of all merchant vessels

Yes, we can conclude that the ship is older than the national average

Step-by-step explanation:

Population mean, μ = 23.6

Sample mean, xbar = 26.7

Sample size, n = 38

H0 : μ = 23.6

H0 : μ > 23.6

The test statistic :

(xbar - μ) ÷ (σ/√(n))

(26.7 - 23.6) ÷ (5.2/√(38))

3.1 / 0.8435513

Test statistic = 3.675

Decision region :

Reject H0 ; if |Tstatistic| > |Tcritical|

Since we are given the sample standard deviation ; we use the T test distribution

df = 38 - 1 = 37

Tcritical at df = 37 ; α = 0.05 ; rigth tailed :

Tcritical(0.05, 37) = 1.687

3.675 > 1.687 ; Hence, we reject H0 and conclude that there is enough evidence that this type of shop is older than the national average.

infinitely many solutions

step-by-step explanation:

we have been given the equation;

2(2x + 3) = -4 + 2(2x + 5)

we need to determine the value of x.

2(2x + 3), we expand this expression to obtain 4x + 6

similarly 2(2x + 5) will become 4x + 10

now we have;

4x + 6 = -4 + 4x + 10

4x + 6 = 4x + 10 - 4

4x + 6 = 4x + 6

the expression on the left hand side is identical to the one on the right hand side. therefore, we are looking at just a single straight line whose equation is;

y = 4x + 6

consequently, we shall have infinitely many solutions

step-by-step explanation:

if you want to solve percent error follow these steps.

1. subtract the accepted value from the experimental value.

2. take the absolute value of step 1.

3. divide that answer by the accepted value.

4. multiply that answer by 100 and add the % symbol to express the answer as a percentage.

if you want to solve percent of change just do this.

1. work out the difference (increase) between the two numbers you are comparing.

2. divide the increase by the original number and multiply the answer by 100. if your answer is a negative number then this is a percentage decrease.

hope this : )