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Lesechka [4]
3 years ago
10

Is smoking during pregnancy associated with premature births? To investigate this question, researchers selected a random sample

of 128 pregnant women who were smokers. The average pregnancy length for this sample of smokers was 265 days. From a large body of research, it is known that length of human pregnancy has a standard deviation of 16 days. The researchers assume that smoking does not affect the variability in pregnancy length. Find the 90% confidence interval to estimate the length of pregnancy for women who smoke. (Note: The critical z -value to use, z c , is: 1.645) ( , ) Your answer should be rounded to 3 decimal places.
Mathematics
1 answer:
horrorfan [7]3 years ago
5 0

Answer:

Confidence interval is 128±2.326 days (between 125.674 days and 130.326 days) in 90% confidence level

Step-by-step explanation:

Confidence interval can be calculated as M±ME where

  • M is the average pregnancy days of smoking women and
  • ME is the margin of error in 90% confidence level.

Margin of Error in 90% confidence level can be calculated using the formula:

ME=\frac{z*s}{\sqrt{N} } where

  • z is the z-value in 90% confidence level (1.645)
  • s is the standard deviation of pregnancy length (16)
  • N is the sample size (128)

putting these  numbers in the formula, we get:

ME=\frac{1.645*16}{\sqrt{128} } =2.326

then confidence interval is 128±2.326 ( between 125.674 and 130.326 ) in 90% confidence level

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3). Find the area of a triangle with a height of 15 cm and a base of 24 cm
tresset_1 [31]

Answer:

answer is 360

Step-by-step explanation:

multiply length times width

3 0
2 years ago
4/16+12/16=how to figure out this problems
sesenic [268]
You add the numerators and keep it over the denominator. 4/16 plus 12/16 is 16/16 and when the same number is the denominator and numerator at the same time, its 1

1 
3 0
3 years ago
You usually buy a 16.5-ounce bottle of shampoo. There is a new bottle that says it gives you 30% more free.
Katarina [22]

Answer:

\frac{x-16.5}{16.5}=0.30

Hopefully, this is your desired setup. (I noticed the formula you have to fill in there.)

Have a good day.

Step-by-step explanation:

Hi.

You could use the percent change formula.

Since we know it is a percent increase then we will do new-old instead of old-new:

\frac{\text{new}-\text{old}}{\old}

x is the new amount of shampoo.

16.5 is the original amount (old) of shampoo.

The percent increase is 30%=0.30 .

So we have the following equation:

\frac{x-16.5}{16.5}=0.30

We could have found the equation like this:

16.5+16.5(0.30)=x

Subtract 16.5 on both sides:

16.5(0.30)=x-16.5

Divide both sides by 16.5:

0.30=\frac{x-16.5}{16.5}

By us of symmetric property of equality:

\frac{x-16.5}{16.5}=0.30

5 0
3 years ago
Read 2 more answers
Please HELP!! ILL GIVE BRAINLEST! QUCIK PLEASE HELP!!
Elena-2011 [213]

Answer:

d. linear; $25/hour

Step-by-step explanation:

From looking at the graph, we have that renting for 2 hours costs $50, for 4 hours costs $100, for 6 hours costs $150, and for 8 hours costs $200. To find out whether the quantities described in the table are linear, we have to see if there is a constant rate of change of price.

For hour 2 to hour 4, we can see that the price increases by $50. This is the same for hour 4 to hour 6 and hour 6 to hour 8. For every 2 hour time interval, the price increases by $50. Therefore, there is a constant rate of change and the quantities described in the table are linear.

Now we have to find the constant rate of change per hour. We know that the price increases by $50 every 2 hours, so, by dividing both the hours and price increase by 2, the price increases by $25 per hour. So the constant rate of change is $25/hour.

Linear. $25/hour

Answer choice d.

I hope you find my answer and explanation to be helpful. Happy studying.

6 0
2 years ago
Guess the rule and add the next number in the sequence.<br> 7, 10, 16, 25, 37,
Delvig [45]

Answer:

Step-by-step explanation:

Let us first closely examine the sequence for any mathematical correlation between the terms of sequence.

It is visualized that the series is progressing with addition of increasing even numbers starting with +6 ( +6, +8, +10, +12, +14, +16, +18 …) in the previous term to obtain next terms of the series. This logic continues for entire series.

The given series is:

1 ,7 ,15 ,25 ,37

Starting with first number of the series

1

1 + 6 = 7

7 + 8 = 15

15 + 10 = 25

25 + 12 = 37

37 + 14 = 51

51 + 16 = 67

67 + 18 = 85

The extended series is

1, 7, 15, 25, 37, 51, 67, 85

4 0
3 years ago
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