Answer: 111.4m
Explanation:
1) Trigonometric ratios
You only need to use tangent ratio.
tangent ratio = opposite-leg / adjacent-leg = balloon height / horizontal distance
2) First, find the height of the ballon when he is watching at an angle of elevation of 28°
tangent ratio = opposite-leg / adjacent-leg = balloon height / horizontal distance
tan(28°) = balloon height/65m ⇒balloon height = tan(28°)×65m
balloon height = 34.56m
3) Second, find the height of the balloon,when he is watching at an angle of elevation of 66°
tan(66°) = height of the balloon / 65m ⇒ height of the balloon = tan(66°)×65m
height of the balloon = 145.99m
4) Vertical distance the balloon ascended while Charlie watched.
Subtract the final initial height from the final height:
145.99m - 34.56m = 111.43m
4) Round to the nearest tenth: 111.4 m
Answer:

Step-by-step explanation:

He isn’t correct because both 0.4 and 0.400 is the equivalent number
Answer:
95.64% probability that pledges are received within 40 days
Step-by-step explanation:
Problems of normally distributed samples are solved using the z-score formula.
In a set with mean
and standard deviation
, the zscore of a measure X is given by:

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.
In this problem, we have that:

What is the probability that pledges are received within 40 days
This is the pvalue of Z when X = 40. So



has a pvalue of 0.9564
95.64% probability that pledges are received within 40 days