I need help with this question asap!!

A theory predicts that the mean age of stars within a particular type of star cluster is 3.3 billion years, with a standard devi

Luden [163]

Answer:

Null hypothesis: $\mu \leq 3.3$

Alternative hypothesis: $\mu > 3.3$

$z=\frac{3.4-3.3}{\frac{0.4}{\sqrt{50}}}=1.768$

Since is a one right tailed test the p value would be:

$p_v =P(z>1.768)=0.039$

Step-by-step explanation:

Data given and notation

$\bar X=3.4$ represent the sample mean

$\sigma=0.4$ represent the population deviation for the sample

$n=50$ sample size

$\mu_o =3.3$ represent the value that we want to test

$\alpha$ represent the significance level for the hypothesis test.

t would represent the statistic (variable of interest)

$p_v$ represent the p value for the test (variable of interest)

State the null and alternative hypotheses to be tested

We need to conduct a hypothesis in order to determine if the mean is higher than 3.3, the system of hypothesis would be:

Null hypothesis: $\mu \leq 3.3$

Alternative hypothesis: $\mu > 3.3$

Compute the test statistic

We know the population deviation, so for this case is better apply a z test to compare the actual mean to the reference value, and the statistic is given by:

$z=\frac{\bar X-\mu_o}{\frac{\sigma}{\sqrt{n}}}$ (1)

z-test: "Is used to compare group means. Is one of the most common tests and is used to determine if the mean is (higher, less or not equal) to an specified value".

We can replace in formula (1) the info given like this:

$z=\frac{3.4-3.3}{\frac{0.4}{\sqrt{50}}}=1.768$

P value

Since is a one right tailed test the p value would be:

$p_v =P(z>1.768)=0.039$

6 0

3 years ago

The graph of y = –3x + 4 is:

Savatey [412]

I believe it is c idk the question really doesn't make that much sense

6 0

3 years ago

Read 2 more answers

In a class in which the final course grade depends entirely on the average of four equally weighted 100-point tests, Joyce has s

d1i1m1o1n [39]

Answer:

66 ≤ f ≤100

Explanation

Mean= ( Σ x ) / n

Mean= sum of scores/ number of subject she took

Now, she already too 3 subject which sum is 85+83+86=254

Now we need to know range of score for her to have (grade) a mark between 80 and 89

Now let take the lower limit mean=80

The lowest score she can get is

Mean = ( Σx) / n

80=(85+83+86+f)/4

80×4= 254+f

Therefore, f= 320-254=66

Therefore the minimum score she can have to have a B is 66.

Then, let take the upper limit mean 89. i.e the maximum she can have so that she don't have an A grade.

Mean = ( Σx) / n

89=( 83+85+86+f)/4

89×4= 254+f

f= 356-254

f=102.

Therefore this shows that she cannot have an A grade in the exam. The maximum score for the exam is 100.

There the range of score is 66 ≤ f ≤100 to have a B grade

66 ≤ f ≤100 answer

Since she cannot score 102 in the examination.

8 0

3 years ago

Brienne and 3 friends bought tickets to the movies. They spent a total of $27.00 on the tickets.

nikdorinn [45]

Answer:

B. 4t=27

Step-by-step explanation:

let t be the price of one ticket,

since there are 4 people buying tickets in total, the price of 4 tickets would be 4t.

so $4t=27$ .

5 0

3 years ago

Read 2 more answers

-3x + 7y = -16<br> -9x + 5y = 16

otez555 [7]

Answer:

x = -4 y =-4

Step-by-step explanation:

Solve for the first variable in one of the equations, then substitute the result into the other equation.

7 0

3 years ago