:

Previously, an organization reported that teenagers spent 24.5 hours per week, on average, on the phone. The organization thinks

Lena [83]

Answer:

We need to develop a one-tail t-student test ( test to the right )

We reject H₀ we find evidence that student spent more than 24,5 hours on the phone

Step-by-step explanation:

Sample size n = 15 n < 30

And we were asked if the mean is higher than, therefore is a one-tail t-student test ( test to the right )

Population mean μ₀ = 24,5

Sample mean μ = 25,7

Sample standard deviation s = 2

Hypothesis Test:

Null Hypothesis H₀ μ = μ₀

Alternative Hypothesis Hₐ μ > μ₀

t (c) = ?

We will define CI = 95 % then α = 5 % α = 0,05 α/2 = 0,025

n = 15 then degree of freedom df = 14

From t-student table we get: t(c) = 2,1448

And t(s)

t(s) = ( μ - μ₀ ) / s/√n

t(s) = (25,7 - 24,5) /2/√15

t(s) = 2,3237

Now we compare t(c) and t(s)

t(c) = 2,1448 t(s) = 2,3237

t(s) > t(c)

Then we are in the rejection region we reject H₀ we have evidence at 95% of CI that students spend more than 24,5 hours per week on the phone

8 0

3 years ago

If j = 10 cm and k = 12.5 cm what is the length of l

leonid [27]

Answer:

22.5

Step-by-step explanation:

3 0

3 years ago

Annabel and Riley were given a homework packet of 120 math questions to finish over the summer.

Lena [83]

Step-by-step explanation:

the answer is 25%

hope it helps!

7 0

2 years ago

The school marching band has a budget of up to $750 to cover 15 new uniforms and

PolarNik [594]

a. The inequality 15x+300≤750 represents the situation.

b. It means that the band can spend at most $30 on each uniform without exceeding the budget.

Step-by-step explanation:

Given,

Budget = $750

Competition fee = $300

Uniforms to make = 15

Let,

x be the amount for each uniform.

a. Write an inequality to represent this situation.

Uniforms to make * Cost per uniform + Competition ≤ Budget

15x+300 ≤ 750

The inequality 15x+300≤750 represents the situation.

b. Solve the inequality and describe what it means in the situation.

$15x+300\leq 750\\15x+300-300\leq 750-300\\15x\leq 450$

Dividing both sides by 15

$\frac{15x}{15}\leq \frac{450}{15}\\x\leq 30$

It means that the band can spend at most $30 on each uniform without exceeding the budget.

Keywords: inequality, division

Learn more about inequality at:

#LearnwithBrainly

3 0

3 years ago

Collect data from all your family members and write down their heights (in cm).

bija089 [108]

Answer:

mode : the value that appears most frequently in a data set

mean : te everage of all number

median : the middle number in a sorted, ascending or descending

range : the difference between the largest and smallest numbers.

ANSWER ;

mode : none

mean : 145.4 ( you need to add all the number and divide by how many your family member)

median : 159

range : 80 ( the largest - the smallest)

4 0

3 years ago