PLEASE HELP! What is the mean of the data represented by this normal distribution?
1 answer:
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Answer:
2,436 students
Step-by-step explanation:
At a 90% confidence level, the z-score is 1.645 and the confidence interval is given by:
Where s is the standard deviation, and n is the sample size.
If they want the length of their confidence interval to be no greater than 0.2, it must be no further than 0.1 from the mean 'X':
Rounding up to the next whole number, the sample size should be 2,436 students.
Answer:
In the year 2019 the number of new cars purchased will reach 15,000.
Step-by-step explanation:
t = 0 corresponds to the number of new cars purchased in 1998. If that is so, we can determine t ( time ) by making our quadratic equation here equal to 15,000 - considering that we want the year the number of cars reaches this value. t here is only the number of years to reach 15,000 cars, so we would have to add that value to 1998, to see the year that the cars will reach 15,000.
The " set up " should look like the following quadratic equation -
20t² + 135t + 3050 = 15,000 - Isolate 0 on one side,
20t² + 135t - 11950 = 0 - From here on let us solve using the quadratic equation formula,
,
... now as you can see we have two solutions, but time can't be negative, and hence our solution is the first one - about 21.3 years. 1998 + 21.3 = ( About ) The year 2019. Therefore, in the year 2019 the number of new cars purchased will reach 15,000.
Answer:
Step-by-step explanation:
We have been given that 1/2 of the children at a party like chocolate ice cream, 2/3 like vanilla ice cream, and 1/3 like chocolate and vanilla.
To find the fraction of children, who like vanilla also like chocolate, We will divide the fraction of children who like chocolate and vanilla by the fraction of children who like vanilla.
Since we know that dividing a fraction by another fraction is same as multiplying the first fraction by the reciprocal of second fraction.
After cancelling out 3 from numerator and denominator of our fraction, we will get,
Therefore, the fraction of those who like vanilla also like chocolate is .