Answer:
27°
Step-by-step explanation:
XWY and VWY are supplementary
∴ XWY + VWY = 180°
∴ XWY = 180° - VWY
XYW and ZYW are supplementary
∴ XYW + ZYW = 180°
∴ XYW = 180° - ZYW
ΔXWY is a right triangle at X
∴ XWY + XYW = 90°
∴ 180° - VWY + 180° - ZYW = 90°
∴ 180° - 6x + 180° - 4x = 90°
∴ 360° - 10x = 90°
∴ 10x = 270°
∴ x = 27°
Answer:
0.15866.
Step-by-step explanation:
We have been given that on average, electricians earn approximately μ= $54,000 per year in the united states. Assume that the distribution for electricians' yearly earnings is normally distributed and that the standard deviation is σ= $12,000. We are asked to find the probability that the sample mean is greater than $66,000.
First of all, we will find the z-score corresponding to 66,000 using z-score formula.




Now, we need to find the probability that z-score is greater than 1 that is
.
Upon using formula
, we will get:

Upon using normal distribution table, we will get:


Therefore, the probability that the sample mean is greater than $66,000 would be 0.15866 or approximately
.
Answer:
a) 68%; b) 99.5%
Step-by-step explanation:
The empirical rule states that 68% of data falls within 1 standard deviation of the mean; 95% of data falls within 2 standard deviations of the mean; and 99.7% of data falls within 3 standard deviations of the mean.
For part a,
We are asked the approximate percentage of women whose platelet counts are within 1 standard deviation of the mean. According to the empirical rule, this is 68%.
For part b,
We are given the endpoints of the interval. The lower endpoint is 181.5; this is 250.8-181.5 = 138.6 away from the mean. Dividing by the standard deviation, 69.3, we have
138.6/69.3 = 2
This is 2 standard deviations away from the mean.
The higher endpoint is 320.1; this is 320.1-181.5 = 138.6 away from the mean. Dividing by the standard deviation, 69.3, we have
138.6/69.3 = 2
This is standard deviations away from the mean.
This means this interval includes about 95% of women.
A variable (m) divided by a number (5)