Question

In: Statistics and Probability

The weight of newborn babies are normally distributed with a mean of 7.62 pounds and a...

The weight of newborn babies are normally distributed with a mean of 7.62 pounds and a standard deviation of 0.61 pounds. If the weight of 22 newborn are randomly selected, what's the probability that their mean weight is more than 7.23 pounds? Round to 4-decimal places

Expert Solution

Solution :

Given that,

mean = = 7.62

standard deviation = = 0.61

n=22

= =7.62

= / n = 0.61 / 22 = 0.13005

P( >7.23 ) = 1 - P( <7.23 )

= 1 - P[( - ) / < (7.23 -7.62) /0.13005 ]

= 1 - P(z <-2.9988 )

Using z table

= 1 - 0.0014

= 0.9986

probability=0.9986

orchestra answered 2 years ago

Suppose that the mean weight of newborn babies is normally distributed with a mean of 6.9...

Suppose that the mean weight of newborn babies is normally distributed with a mean of 6.9 pounds and a standard deviation of 0.8 pound. A developmental psychologist wants to test whether newborn babies of mothers who use drugs during pregnancy differ in weight from the average baby. The psychologist takes a random sample of 30 mothers who used drugs during pregnancy and computes the mean birth weight of these mothers’ babies. This sample of 30 mothers has a sample mean...

The weights for newborn babies is approximately normally distributed with a mean of 6.9 pounds and...

The weights for newborn babies is approximately normally distributed with a mean of 6.9 pounds and a standard deviation of 1.1 pounds. Consider a group of 1200 newborn babies: 1. How many would you expect to weigh between 6 and 9 pounds? 2. How many would you expect to weigh less than 8 pounds? 3. How many would you expect to weigh more than 7 pounds? 4. How many would you expect to weigh between 6.9 and 10 pounds?

The weights for newborn babies is approximately normally distributed with a mean of 6.4 pounds and...

The weights for newborn babies is approximately normally distributed with a mean of 6.4 pounds and a standard deviation of 1.4 pounds. Consider a group of 1100 newborn babies: 1. How many would you expect to weigh between 4 and 8 pounds? 2. How many would you expect to weigh less than 7 pounds? 3. How many would you expect to weigh more than 6 pounds? 4. How many would you expect to weigh between 6.4 and 10 pounds?

he weights for newborn babies is approximately normally distributed with a mean of 5.1 pounds and...

he weights for newborn babies is approximately normally distributed with a mean of 5.1 pounds and a standard deviation of 1.4 pounds. Consider a group of 1500 newborn babies: 1. How many would you expect to weigh between 3 and 6 pounds? 2. How many would you expect to weigh less than 5 pounds? 3. How many would you expect to weigh more than 4 pounds? 4. How many would you expect to weigh between 5.1 and 8 pounds? Get...

The weights for newborn babies is approximately normally distributed with a mean of 5lbs and a...

The weights for newborn babies is approximately normally distributed with a mean of 5lbs and a standard deviation of 1.5lbs. Consider a group of 1,000 newborn babies: How many would you expect to weigh between 4-7lbs? How many would you expect to weigh less than 6lbs? How many would you expect to weigh more than 5lbs? How many would you expect to weigh between 5-10lbs?

The birthweight of newborn babies is Normally distributed with a mean of 3.39 kg and a...

The birthweight of newborn babies is Normally distributed with a mean of 3.39 kg and a standard deviation of 0.55 kg. (a) Find the probability that a baby chosen at random will have a birthweight of over 3.5 kg. (b) Find the probability that an SRS of 16 babies will have an average birthweight of over 3.5 kg. (c) Find the probability that an SRS of 100 babies will have an average birthweight of over 3.5 kg. (d) What range...

The weights of American newborn babies are normally distributed with a mean of 119.54 oz (...

The weights of American newborn babies are normally distributed with a mean of 119.54 oz ( about 7 pounds 8 ounces) and a population standard deviation of .61 oz. A sample of 11 newborn babies is randomly selected from the population. (a) find the standard error of the sampling distribution. Round your answer to 4 decimal places. (b) Using your answer to part (a), what is the probability that in a random sample of 11 newborn babies, the mean weight...

2. The weights of American newborn babies are normally distributed with a mean of 119.54 oz...

2. The weights of American newborn babies are normally distributed with a mean of 119.54 oz (about 7 pounds 8 ounces) and a population standard deviation of 0.67 oz. A sample of 14 newborn babies is randomly selected from the population. (a) Find the standard error of the sampling distribution. Round your answer to 4 decimal places. (b) Using your answer to part (a), what is the probability that in a random sample of 14 newborn babies, the mean weight...

In the U.S., newborn babies weight an average of 7.2 pounds (μ). The standard deviation is...

In the U.S., newborn babies weight an average of 7.2 pounds (μ). The standard deviation is 1.22 pounds (σ). The population distribution of birth weights is roughly Normal. You draw a simple random sample of 60 births from the population and find that the sample mean is 7.4 pounds. NOTE: Use the most precise estimate of z or z* you can in these problems as in all your written results. Draw a picture of the distribution, label, and shade as...

The weight (in pounds) for a population of school-aged children is normally distributed with a mean...

The weight (in pounds) for a population of school-aged children is normally distributed with a mean equal to 138 ± 23 pounds (μ ± σ).Suppose we select a sample of 100 children (n = 100) to test whether children in this population are gaining weight at a 0.05 level of significance. Part (a) What are the null and alternative hypotheses? H0: μ = 138 H1: μ < 138 H0: μ = 138 H1: μ ≠ 138 H0: μ ≤ 138...