Answer:
The approximate percentage of SAT scores that are less than 865 is 16%.
Step-by-step explanation:
The Empirical Rule states that, for a normally distributed random variable:
Approximately 68% of the measures are within 1 standard deviation of the mean.
Approximately 95% of the measures are within 2 standard deviations of the mean.
Approximately 99.7% of the measures are within 3 standard deviations of the mean.
In this problem, we have that:
Mean of 1060, standard deviation of 195.
Empirical Rule to estimate the approximate percentage of SAT scores that are less than 865.
865 = 1060 - 195
So 865 is one standard deviation below the mean.
Approximately 68% of the measures are within 1 standard deviation of the mean, so approximately 100 - 68 = 32% are more than 1 standard deviation from the mean. The normal distribution is symmetric, which means that approximately 32/2 = 16% are more than 1 standard deviation below the mean and approximately 16% are more than 1 standard deviation above the mean. So
The approximate percentage of SAT scores that are less than 865 is 16%.
Answer:
There is a 40.96% probability that he answers exactly 1 question correctly in the last 4 questions.
Step-by-step explanation:
For each question, there are only two possible outcomes. Either it is correct, or it is not. This means that we use the binomial probability distribution to solve this problem.
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 combinatios of x objects from a set of n elements, given by the following formula.
And p is the probability of X happening.
In this problem we have that:
There are four questions, so n = 4.
Each question has 5 options, one of which is correct. So
What is the probability that he answers exactly 1 question correctly in the last 4 questions?
This is
There is a 40.96% probability that he answers exactly 1 question correctly in the last 4 questions.
My guess...
⊕⊕⊕
Answer:
He performed better in the 800 m race
Step-by-step explanation:
Obtain the standardized score for each event :
Zscore = (score - mean) / standard deviation
1000 meter :
Mean = 4.5 ; Standard deviation = 0.75 ; x = 4.1
Zscore = (4.1 - 4.5) / 0.75
Zscore = - 0.4 / 0.75 = - 0.5333
800 meter :
Mean = 3.2 ; Standard deviation = 0.4 ; x = 3
Zscore = (3 - 3.2) / 0.4
Zscore = - 0.2 / 0.4 = - 0.5
-0.5 > - 0.533
Hence, he performed better in the 800 m race
the square root of 25 is 5
5x5=25
2 Dewey you can still go to get
