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A sleep time of 15.9 hours per day for a newborn baby is at the 10h percentile of the distribution of sleep times for all newbor

Step2247 [10]

The mean time in hours per day for newborn babies is 16.5 hours ⇒ D

Step-by-step explanation:

A sleep time of 15.9 hours per day for a newborn baby is at the 10th

percentile of the distribution of sleep times for all newborn babies

Assuming the distribution is normal with a standard deviation of

0.5 hour

To find the mean time let us do that

1. Use the normal distribution table to find the corresponding z-score

for 10th percentile

2. Use the rule μ = x - zσ, where μ is the mean, σ is the standard

deviation and x is the score

3. Substitute the values of x, σ and z in the rule to find μ

Look to the normal distribution table to find z-score that equivalent

to the area = 10/100 = 0.1 (10th percentile)

∵ z-score = -1.28

∵ σ = 0.5 hour

∵ x = 15.9

∵ μ = x - zσ

- Substitute the values in the rule

∴ μ = 15.9 - (-1.28)(0.5)

∴ μ = 15.9 + 0.64

∴ μ = 16.54 ≅ 16.5 hours

The mean time in hours per day for newborn babies is 16.5 hours

Learn more:

You can learn more about the normal distribution curve in brainly.com/question/8799684

#LearnwithBrainly

6 0

2 years ago

How many numbers between 2 and 500 are divisible by 3 ?

beks73 [17]

Answer:

Your answer is 226 numbers.

6 0

2 years ago

Read 2 more answers

Please help, I’ll mark your answer as brainliest!

statuscvo [17]

Answer:

$(x-230)^2+(y-220)^2=6100$

Step-by-step explanation:

The equation for a circle is $(x-h)^2+(y-k)^2=r^2$ , where $(h,k)$ is the vertex of the circle and $r$ is the radius. Immediately, since the center of the circle is given, we know what $h$ and $k$ are. $h$ is 230 and $k$ is 220.

The only thing we need to find is the radius, which will just be the distance from the center (230,220) to a point on the circumference (170,170). The distance between them can be calculated using the distance formula, which is really just the Pythagorean Theorem rearranged. The formula states that $d=\sqrt{x^2+y^2}$ , where $x$ is the change in the x-coordinates of the two points and $y$ is the change in the y-coordinates of the two points. Plug-in $x$ for 60 and $y$ for 50 to get $d=\sqrt{50^2+60^2}$ . Solve for $d$ , arriving at $\sqrt{6100}$ . Therefore, the radius of the circle is $\sqrt{6100}$ .