Answer:
1.33
Step-by-step explanation:
y2-y1/x2-x1
=11+1/-3-6
=12/-9
=-4/3
=1.33
Answer: 80 ft²
Step-by-step explanation:
The area of a trapezoid is one half the product of the height and the sum of the lengths of the bases.
(6 + 10) * 0.5 * 10 = 80 (ft²)
Answer:
Step-by-step explanation:
Hello!
X: the lifespan of a new computer monitor of Glotech.
The average life is μ= 85 months and the variance δ²= 64
And a sample of 122 monitors was taken.
You need to calculate the probability that the sample mean is greater than 86.6 months.
Assuming that the variable has a normal distribution X~N(μ;δ²), then the distribution of the sample mean is X[bar]~N(μ;δ²/n)
To calculate this probability you have to work using the sampling distribution and the following formula Z= (X[bar]-μ)/δ/√n ~N(0;1)
P(X[bar]>86.6)= 1 - P(X[bar]≤86.6)
1 - P(Z≤(86.6-85)/(8/√122))= 1 - P(Z≤2.21)= 1 - 0.98645= 0.013355
The probability of the sample mean is greater than 0.013355
I hope this helps!
Answer:
2
Step-by-step explanation:
2
Answer:
A) Population standard deviation is known.
B) Option 3
H0: μ =520,
H1: μ ≠ 520
z > 1.96 or z < -1.96
Step-by-step explanation:
A) The normal distribution should be used for the sample mean because the population standard deviation is known. Usually, when the standard deviation is unknown we don't use normal distribution except there is an underlying normal approximation.
B) Null Hypothesis:H0: μ =520,
Alternative hypothesis H1: μ ≠ 520
At 5% level of significance, from standard tables, we will reject H0 if;
The test statistic; z > 1.96 or z < -1.96
