A group of students randomly exit the school bus after returning from a field trip. You want to calculate the probability of two
2 answers:
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Answer:
No, there is not enough evidence to support the claim that true average task time with armor is less than 2 seconds.
Step-by-step explanation:
This is a hypothesis test for the population mean.
The claim is that true average task time with armor is less than 2 seconds.
Then, the null and alternative hypothesis are:
The significance level is 0.01.
The sample has a size n=52.
The sample mean is M=1.95.
As the standard deviation of the population is not known, we estimate it with the sample standard deviation, that has a value of s=0.2.
The estimated standard error of the mean is computed using the formula:
Then, we can calculate the t-statistic as:
The degrees of freedom for this sample size are:
This test is a left-tailed test, with 51 degrees of freedom and t=-1.803, so the P-value for this test is calculated as (using a t-table):
As the P-value (0.039) is bigger than the significance level (0.01), the effect is not significant.
The null hypothesis failed to be rejected.
There is not enough evidence to support the claim that true average task time with armor is less than 2 seconds.
Answer:
The ultra-marathon Idita Rod Trail is about 38 times longer than the Boston Marathon.
Step-by-step explanation:
Let
x -----> the length of the Boston Marathon in meters
y -----> the length of the Idita rod Trail Invitational ultra-marathon in meters
we have
we know that
To find out how many times as long is the course of the Idita rod Trail ultra-marathon as that of the Boston Marathon, divide the length of the Idita rod Trail Invitational ultra-marathon by the length of the Boston Marathon
so
Remember that
To divide two numbers in scientific notation, divide their coefficients and subtract their exponents
therefore
The ultra-marathon Idita Rod Trail is about 38 times longer than the Boston Marathon.
Answer:
0.0045 = 0.45% probability that less than two of them ended in a divorce
Step-by-step explanation:
For each marriage, there are only two possible outcomes. Either it ended in divorce, or it did not. The probability of a marriage ending in divorce is independent of any other marriage. This means that the binomial probability distribution is used to solve this question.
Binomial probability distribution
The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.
In which is the number of different combinations of x objects from a set of n elements, given by the following formula.
And p is the probability of X happening.
55% of marriages in the state of California end in divorce within the first 15 years.
This means that
Suppose 10 marriages are randomly selected.
This means that
What is the probability that less than two of them ended in a divorce?
This is
In which
0.0045 = 0.45% probability that less than two of them ended in a divorce