Answer:
Its A
Step-by-step explanation:
Answer:
the confidence interval for the true weight of the specimen is;
4.1593 ≤ μ ≤ 4.1611
Step-by-step explanation:
We are given;
Standard deviation; σ = 0.001
Sample size; n = 8
Average weight; x¯ = 4.1602
We are given a 99% confidence interval and the z-value at this interval is 2.576
Formula for confidence interval is;
CI = x¯ ± (zσ/√n)
Plugging in the relevant values, we have;
CI = 4.1602 ± (2.576 × 0.001/√8)
CI = 4.1602 ± 0.000911
CI = (4.1602 - 0.000911), (4.1602 + 0.000911)
CI ≈ (4.1593, 4.1611)
Thus, the confidence interval for the true weight will be expressed as;
4.1593 ≤ μ ≤ 4.1611
Where μ represents the true weight
Answer:
Step-by-step explanation:
Given that:
mean (μ) = 476 grams, standard deviation (σ) = 36 grams. P(z) = 19%
The z score shows by how many standard deviation the raw score is above or below the mean. It is given by the equation:
Since the 19% weigh more, therefore 81% (100% - 19%) weigh less.
From the normal distribution table, the z score that corresponds to a probability of 81%(0.81) = 0.87
We substitute z = 0.88 in the z score equation to find the raw score. Therefore:
x ≅ 507 grams
Therefore 19% of fruits weigh more than 507 grams
Answer:
Her speed on the summit was 35 mph.
Step-by-step explanation:
Her speed on the summit was "x" mph while her speed while climbing was "x - 10" mph. The distance she rode uphill was 55 miles and on the summit it was 28 miles. The total time she explored the mountain was 3 hours. Therefore:
time uphill = distance uphill / speed uphill = 55 / (x - 10)
time summit = distance summit / speed summit = 28 / x
total time = time uphill + time summit
3 = [55 / (x - 10)] + 28 / x
3 = [55*x + 28*(x - 10)]/[x*(x - 10)]
3*x*(x - 10) = 55*x + 28*x - 280
3x² - 30*x = 83*x - 280
3x² - 113*x + 280 = 0
x1 = {-(-113) + sqrt[(-113)² - 4*(3)*(280)]}/(2*3) = 35 mph
x2 = {-(-113) - sqrt[(-113)² - 4*(3)*(280)]}/(2*3) = 2.67 mph
Since her speed on the uphill couldn't be negative the speed on the summit can only be 35 mph.
