x 2 Problem Mathematical Q 9. PRACTICE Be Precise Ty has two pieces of wood. Use or to compare the pieces of wood. WWW

A random sample of 144 recent donations at a certain blood bank reveals that 81 were type A blood. Does this suggest that the ac

Reptile [31]

Answer:

Null hypothesis: $p=0.4$

Alternative hypothesis: $p \neq 0.4$

$z=\frac{0.5625 -0.4}{\sqrt{\frac{0.4(1-0.4)}{144}}}=3.98$

$p_v =2*P(z>3.98)=0.0000689$

Since the p value is very low compared to the significance level we have enough evidence to reject the null hypothesis and we can conclude that the true percent of people with type A of blood is significantly different from 0.4 or 40%

Step-by-step explanation:

Information given

n=144 represent the random sample taken

X=81 represent the number of people with type A blood

$\hat p=\frac{81}{144}=0.5625$ estimated proportion of people with type A blood

$p_o=0.4$ is the value that we want to verify

$\alpha=0.01$ represent the significance level

z would represent the statistic

$p_v{/tex} represent the p value Hypothesis to testWe want to test if the percentage of the population having type A blood is different from 40%.: Null hypothesis:[tex]p=0.4$

Alternative hypothesis: $p \neq 0.4$

the statistic is given by:

$z=\frac{\hat p -p_o}{\sqrt{\frac{p_o (1-p_o)}{n}}}$ (1)

Replacing the info given we got:

$z=\frac{0.5625 -0.4}{\sqrt{\frac{0.4(1-0.4)}{144}}}=3.98$

Now we can calculate the p value with this probability taking in count the alternative hypothesis:

$p_v =2*P(z>3.98)=0.0000689$

Since the p value is very low compared to the significance level we have enough evidence to reject the null hypothesis and we can conclude that the true percent of people with type A of blood is significantly different from 0.4 or 40%

3 0

3 years ago

A student has gotten the following grades on his tests. What is the minimum grade he must get on the last test in order to have

steposvetlana [31]

In order to get an 81 average,
the student has to get 81x5=405

71+96+90+73+?=405
330+?=405
405-330=75
he needs to get an 75

3 0

3 years ago

The volume of a tetrahedron is 1 6 of the volume of a parallelepiped whose sides are formed using the vectors coming out of one

Irina18 [472]

Answer: The volume of the tetrahedron is 2 units.

Step-by-step explanation:

Let A = (1, 1, 1)

B = (1, 5, 5)

C = (2, 2, 1)

The volume of a tetrahedron is given as

V = (1/6)|AB, AC, AD|

Where |AB, AC, AD| is the determinant of the matrix of AB, AC, AD.

We need to determine AB, AC, and AD

Suppose A = (a1, a2, a3)

B = (b1, b2, b3)

C = ( c1, c2, c3)

AB = ( b1 - a1, b2 - a2, b3 - a3)

Similarly for AB, AC, BC, etc.

AB = (1 - 1, 5 - 1, 5 - 1)

= (0, 4, 4)

AC = (1, 0, 2)

AD = (1, 1, 0)

Volume =

(1/6) |0 4 4|

|1 0 2|

|1 1 0|

= (1/6)[0(0 - 2) - 4(0 - 2) + 4(1 - 0)

= (1/6)(0 + 8 - 4)

= (1/6)(12)

V = 12/6 = 2 units

5 0

3 years ago

If x<0 and y>0, determine the sign of the real number x-y/xy ...?

Ludmilka [50]

If x<0 and y>0, then the sign of the real number x-y/xy would be positive. <span>If x is negative and y is positive then x-y is negative and xy is negative. A negative number divided by another negative number would be positive. Hope this answers the question.</span>

4 0

2 years ago

What is the what is the answer

ElenaW [278]

The answer would be D. 18/6. We can figure this out because in the question, it says that each shape is worth one whole. There are three shapes so that means when added, the sum is 3 and 18/6, when reduced is 3.
I hope this helped! :-)

3 0

3 years ago