Can someone help me with this please

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

Question number 1: 5/8 (16b+24) -1/2b Question number 2: 3/4 (16/64 + 12a) -9a

Sophie [7]

Answer:

Problem 1. (19/2)b + 15

Problem 2. 3/16

Step-by-step explanation:

Question number 1

5/8 (16b+24) -1/2b =

= (5/8) * (16/1) * b + (5/8) * 24 - (1/2)b

= 10b + 15 - (1/2)b

= (20/2)b - (1/2)b + 15

= (19/2)b + 15

Question number 2

3/4 (16/64 + 12a) -9a =

= (3/4) * (16/64) + (3/4) * 12a - 9a

= (3 * 16)(4 * 64) + (3/4) * (12/1) * a - 9a

= (3 * 1)(4 * 4) + (3 * 12)/(4 * 1) * a - 9a

= 3/16 + (3 * 3)/(1 * 1) * a - 9a

= 3/16 + 9a - 9a

= 3/16

5 0

3 years ago

Please please help mane :((( give explanation plsss :(((

Deffense [45]

Answer:

$2x - 1 > 4x + 6 \\ 2x - 2x - 1 > 4x - 2x + 6 \\ - 1 > 2x + 6 \\ - 6 - 1 > 2x \\ - 7 > 2x \\ \frac{ - 7}{2} > x$

I hope I helped you^_^

3 0

3 years ago

BIG IDEAS MATH

sveticcg [70]

Answer:

The required expression is $\frac{y}{4}-3$ .

The value of the expression when y=20 is 2.

Step-by-step explanation:

Consider the provided phase.

3 less than the quotient of a number y and 4

The quotient of a number y and 4 can be written as: $\frac{y}{4}$

Now 3 less than the quotient of a number y and 4 can be written as:

$\frac{y}{4}-3$

Hence, the required expression is $\frac{y}{4}-3$ .

Now evaluate when y=20.

Substitute y=20 in above expression.

$\frac{20}{4}-3$

$5-3$

$2$

Hence, the value of the expression when y=20 is 2.

3 0

4 years ago

The product of a number and 3 increased by 9 is less than -42 TRANSLATE

nikitadnepr [17]

Answer:

3x+9 < - 42

Step-by-step explanation:

4 0

3 years ago