# Thread:

1. ## Find the mean and standard deviation of the sum or difference of independent random v

what should i do for A?? and for B, is it asking me to convert all the temperatures to Fahrenheit?
Attached Thumbnails

2. ## Re: Find the mean and standard deviation of the sum or difference of independent rand

They are asking for $E[X-550]$, and $\textrm{Var}(X-550)$. You should have some formulas that should make the preceding quite simple.

3. ## Re: Find the mean and standard deviation of the sum or difference of independent rand

yes i figured out how to get the mean... i just simply take the temperatures that are off target and minus it to 550... i got that part but what i don't know how to get is the standard deviation.... would you happen to know how to calculate that based on my problem??
{"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 2, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "github"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "english_confidence": 0.924153208732605, "perplexity_flag": "head"}