Write 7.530 in word form.

A random sample of 160 car purchases are selected and categorized by age. The results are listed below. The age distribution of

seraphim [82]

Answer:

The claim that all ages have purchase rates proportional to their driving rates is false.

Step-by-step explanation:

The complete question is:

A random sample of 160 car accidents are selected and categorized by the age of the driver determined to be at fault. The results are listed below. The age distribution of drivers for the given categories is 18% for the under 26 group, 39% for the 26-45 group, 31% for the 45-65 group, and 12% for the group over 65. Calculate the chi-square test statistic used to test the claim that all ages have crash rates proportional to their driving rates.

Age >26 26-45 46-65 45<

Drivers 66 39 25 30

A) 95.431

B)101.324

C)85.123

D)75.101

Solution:

In this case we need to test whether there is sufficient evidence to warrant rejection of the claim that all ages have crash rates proportional to their driving rates.

A Chi-square test for goodness of fit will be used in this case.

The hypothesis can be defined as:

H₀: The observed frequencies are same as the expected frequencies.

Hₐ: The observed frequencies are not same as the expected frequencies.

The test statistic is given as follows:

$\chi^{2}=\sum{\frac{(O-E)^{2}}{E}}$

The values are computed in the table.

The test statistic value is 75.10.

The degrees of freedom of the test is:

n - 1 = 4 - 1 = 3

Compute the p-value of the test as follows:

p-value < 0.00001

*Use a Chi-square table.

p-value < 0.00001 < α = 0.05.

So, the null hypothesis will be rejected at any significance level.

Thus, there is sufficient evidence to warrant rejection of the claim that ages have crash rates proportional to their driving rates.

3 0

2 years ago

A recent survey of 8,000 high school students found that the mean price of a prom dress was $195.00 with a standard deviation of

KiRa [710]

To calculate the z-statistic, we must first calculate the standard error.

Standard error is standard deviation divided by the square root of the population. In this case, it is equal to 2.68.

The z-score is defined the distance from the sample to the population mean in units of standard error.

z = (195 – 208)/2.68 = -4.86

5 0

2 years ago

Of the 400 eighth-graders at pascal middle school, 117 take algebra, 109 take advanced computer, and 114 take industrial technol

Hatshy [7]

If 164 of the 400 eighth-graders take none of these courses, then 400-164=236 students take some courses.

Let x students take all three courses, then:

1. 70-x take only both algebra and advanced computer,

2. 34-x take only both algebra and industrial technology,

3. 29-x take only both advanced computer and industrial technology.

Now let's count how many student take only one course:

1. 117-(x+34-x+70-x)=13+x take algebra,

2. 109-(x+29-x+70-x)=10+x take advanced computer,

3. 114-(x+29-x+34-x)=51+x take industrial technology.

Now count all students that take some courses:

51+x+10+x+13+x+29-x+34-x+70-x+x=236,

x=236-51-10-13-29-34-70,

x=29.

Answer: all three courses take 29 students.

6 0

2 years ago

Read 2 more answers

An office building has two elevators. One elevator starts out on the 4th floor, 35 feet above the ground, as it’s defending at a

iren2701 [21]

The system of equations are y = 35 - 2.2x and y = 1.7x

Solution:

Given that, office building has two elevators.

One elevator starts out on the 4th floor, 35 feet above the ground, as it’s descending at a rate of 2.2 feet per second

Let "x" be the number of seconds for which the elevator is descending

Therefore, for "x" seconds the descended feet is 2.2x feet

The elevator is at 4 th floor, 35 feet above ground

Therefore, from 35 feet, the elevator has descended 2.2x feet for "x" seconds

Let "y" be the final position of elevator after "x" seconds

Therefore,

y = 35 - 2.2x

The other elevator starts out at ground level and is rising at a rate of 1.7 feet per second

Here, the elevator is rising at a rate of 1.7 feet per second

Therefore, for "x" seconds, the elevator has raised 1.7x feet

Here the elevator is at ground level, therefore

y = 1.7x

Thus the system of equations are y = 35 - 2.2x and y = 1.7x

6 0

2 years ago

A package of hamburgers contains 8 patties and costs $7.50. Part A.) Luna has to buy at least 16 packages for an upcoming picnic

Rus_ich [418]

Answer:

Part A) $p\geq 128\ patties$

Part B) She will spend more than $\$142.50$

Step-by-step explanation:

Let

p-----> the number of hamburger patties

Part A) Luna has to buy at least 16 packages for an upcoming picnic

$p\geq 16*8$

$p\geq 128\ patties$

Part B) Suppose she actually needs more than 150 hamburgers. How much will she spend?

Let

c---------> the total cost

step 1

Divide 150 hamburgers by 8 (a package of hamburgers)

so

$\frac{150}{8} =18.75\ package$

round to the nearest whole number

$18.75=19\ package$ ----> the minimum number of packages

step 2

$c>19*\$7.50$

$c>\$142.50$

7 0

2 years ago