Question

1. In 90 rolls of a six-sided die, the outcome of 1 appears 16 times. State whether the difference between what occurred and what you would have expected by chance is statistically significant. Is the difference between what occurred and what is expected by chance statistically significant?

No

Yes

2. What is statistical inference? Why is it important?

A.Statistical inference is the process of determining if the difference between what is observed and what is expected is too great to be explained by chance alone. It is important because we expect small deviations to occur by chance.

B.Statistical inference is the process of making a conclusion about a population from results for a sample. It is important because the goal of most statistical studies is to learn something about an entire population.

C.Statistical inference refers to the process of designing and conducting an experiment. It is important because well designed experiments are critical in order to obtain valid data from a sample.

D.Statistical inference refers to the process of collecting data about the sample. It is important because it is rarely possible or plausible to collect data from an entire population.

3. The lengths of pregnancy terms for a particular species of mammal are nearly normally distributed about a mean pregnancy length with a standard deviation of 15 days. About what percentage of births would be expected to occur within 45 days of the mean pregnancy length?

About _____% of births would be expected to occur within 45 days of the mean pregnancy length. (Type an integer or a decimal.)

Answer 1

1)

Probability of coming one  16 times will be

Because probability of coming 1 will be 1/6

Probabibility will be

Probability of not coming one will be

So proabibility will be

Vale of p is less than 0.05

So it is  is statistically significant.

he difference between what occurred and what is expected by chance statistically significant

3)

The lengths of pregnancy terms for a particular species of mammal are nearly normally distributed about a mean pregnancy length with a standard deviation of 15 days

We have to find the percentage of births would be expected to occur within 45 days of the mean pregnancy length

About 99.7% of the births would be within 45 days of the mean.

45 days is 3  standard deviations past the mean.

The Empirical Rule states that about 99.7% of the values in a normal distribution fall within 2 standard deviations of the mean.

In statistics, the 68–95–99.7 rule, also known as the empirical rule

is a shorthand used to remember the percentage of values that lie within a band around the mean in a normal distribution with a width of two, four and six standard deviations, respectively; more accurately, 68.27%,95.45% and 99.73% of the values lie

2)

Option B is correct

Statistical inference is the process of making a conclusion about a population from results for a sample. It is important because the goal of most statistical studies is to learn something about an entire population.