Find the product: (5/3)(2/3)(2/1)

Starting in the 1970s, medical technology allowed babies with very low birth weight (VLBW, less than 1500 grams, about 3.3 pound

cluponka [151]

Answer:

The test statistic value using the VLBW babies as group 1 is z=-2.76±0.01 and the P-value for the test (±0.0001) is 0.0030.

Step-by-step explanation:

This is a hypothesis test for the difference between proportions.

The claim is that the proportion of persons with normal birth weight that graduates from high school is significantly greater than the proportion of persons with very low birth weight that graduates from high school.

Then, the null and alternative hypothesis are:

$H_0: \pi_1-\pi_2=0\\\\H_a:\pi_1-\pi_2> 0$

The significance level is 0.05.

The sample 1 (VLBW group), of size n1=244 has a proportion of p1=0.77049.

$p_1=X_1/n_1=188/244=0.77049$

The sample 2 (control group), of size n2=247 has a proportion of p2=0.79757.

$p_2=X_2/n_2=197/247=0.79757$

The difference between proportions is (p1-p2)=-0.02708.

$p_d=p_1-p_2=0.77049-0.79757=-0.02708$

The pooled proportion, needed to calculate the standard error, is:

$p=\dfrac{X_1+X_2}{n_1+n_2}=\dfrac{188+197}{244+247}=\dfrac{385}{491}=0.988$

The estimated standard error of the difference between means is computed using the formula:

$s_{p1-p2}=\sqrt{\dfrac{p(1-p)}{n_1}+\dfrac{p(1-p)}{n_2}}=\sqrt{\dfrac{0.988*0.012}{244}+\dfrac{0.988*0.012}{247}}\\\\\\s_{p1-p2}=\sqrt{0.00005+0.00005}=\sqrt{0.0001}=0.0098$

Then, we can calculate the z-statistic as:

$z=\dfrac{p_d-(\pi_1-\pi_2)}{s_{p1-p2}}=\dfrac{-0.02708-0}{0.0098}=\dfrac{-0.02708}{0.0098}=-2.76$

This test is a left-tailed test, so the P-value for this test is calculated as (using a z-table):

$P-value=P(t$

As the P-value (0.0030) is smaller than the significance level (0.05), the effect issignificant.

The null hypothesis is rejected.

There is enough evidence to support the claim that the proportion of persons with normal birth weight that graduates from high school is significantly greater than the proportion of persons with very low birth weight that graduates from high school.

3 0

3 years ago

Tyler used 6 gallons of paint to paint 4/7 of a fence. How many gallons will it take to paint the whole fences

vredina [299]

Answer:

Step-by-step explanation:

(6 gal)/(4/7 fence) = (21/2 gal)/fence = (10.5 gal)/fence

5 0

2 years ago

Melania has two jobs. During the day she works as an office clerk, and in the evening she works as a cashier. her office job pay

bulgar [2K]

Lets x = # of hours Melania works at office clerk
and y = # of hours Melania works as a cashier

x + y = 38 so x = 38 - y
13x + 9.25y = 434

substitute x = 38 - y into 13x + 9.25y = 434

13x + 9.25y = 434
13(38 - y) + 9.25y = 434
494 - 13y + 9.25y = 434
-3.75y = -60
y = 16
x = 38 - y so x = 38 - 16 = 22

answer
Melania works at office clerk = 22 hours
Melania works as a cashier = 16 hours

7 0

3 years ago

I really need help with this last problem

gogolik [260]

Answer:

Step-by-step explanation:

a. Profit, p, earned from selling x hats when hat will be sold for $12 each:

p = 12x

b. To recover the cost of making the 200 hats which is $1500, profit, p >= cost:

p = 12x >= 1500

x >= 1500/12 = 12.5

So the minimum number of hats that must be sold = 13

c. New hat price = $15 so p = 15x

p = 15x >= 1500

x >= 1500/15 = 10

So the new minimum = 10 which is 3 fewer.

3 0

3 years ago

Read 2 more answers

Help, please! 3x−y=12 x=−6y−15 What is the solution? Show work!

KiRa [710]

Answer:

everything can be found in the picture above. I hope it helps

4 0

3 years ago