In a study of 250 adults, the mean heart rate was 70 beats per minute. Assume the population of heart rates is known to be appro
ximately normal with a standard deviation of 12 beats per minute. What is the 99% confidence interval for the mean beats per minute?
68.9 − 76.3
70 − 72
61.2 − 72.8
68 − 72
68.9 − 76.3
70 − 72
61.2 − 72.8
68 − 72
1 answer:
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Part A)
The given equation is:
The radicand or discriminant(d) of the equation will be:
Since the discriminant is equal to 0, the given quadratic equation has only 1 root. In other words we can say the the given equation is a perfect square.
Part B)
The given equation is:
We can solve this expression by factorization. Factors of middle term are to be made in such a way that their product equals the product of first and third term and sum is equal to the middle term i.e. product should be 4x² and sum should be -4x.
So the two such terms are -2x and -2x. Using the factors and simplifying the equation by taking common we get:
The given equation is:
The radicand or discriminant(d) of the equation will be:
Since the discriminant is equal to 0, the given quadratic equation has only 1 root. In other words we can say the the given equation is a perfect square.
Part B)
The given equation is:
We can solve this expression by factorization. Factors of middle term are to be made in such a way that their product equals the product of first and third term and sum is equal to the middle term i.e. product should be 4x² and sum should be -4x.
So the two such terms are -2x and -2x. Using the factors and simplifying the equation by taking common we get: